HomeMy WebLinkAbout2022-02 Twin Falls Filer Avenue RSA Report_FINAL ROAD
• 1 , SAFETY AUDIT
, REPORT
FILER AVENUE
TWIN FALLS, IDAHO
PREPARED FOR: PREPARED BY:
CITY OF TWIN FALLS DKS ASSOCIATES
�' 8� TWIN FALLS Idaho
7 People Serving People '
Erin Steel, PE Brian Chandler, PE, PTOE, RSP21B
Matt Ricks, PE, PTOE
LOCAL HIGHWAY TECHNICAL
ASSISTANCE COUNCIL Veronica Sullivan RSP1
Al M&C
Amanda LaMott, PE
' 719 SECOND AVENUE, SUITE 1250, SEATTLE, WA 98104 • 206.382.9800 • DKSASSOCIATES.COM
SHAPING A SMARTER TRANSPORTATION EXPERIENCE AN EMPLOYEE-OWNED COMPANY
TABLE OF CONTENTS
EXECUTIVESUMMARY.........................................................................................................................................6
INTRODUCTION...................................................................................................................................................8
RSAPROCESS.........................................................................................................8
SAFETYDATA.....................................................................................................................................................10
INTERSECTION OF FILER AVENUE AND WASHINGTON STREET N......................................................................11
INTERSECTION ISSUES ........................................................................................... 11
FILER AVENUE AND WASHINGTON STREET N: RECOMMENDATIONS..................................... 12
ROADWAY SEGMENT FROM WASHINGTON STREET N TO HARRISON STREET..................................................... 13
ROADWAY ISSUES ................................................................................................. 13
SEGMENT FROM WASHINGTON STREET N TO HARRISON STREET: RECOMMENDATIONS ............ 14
INTERSECTION OF FILER AVENUE AND HARRISON STREET............................................................................... 16
INTERSECTION ISSUES ........................................................................................... 16
FILER AVENUE AND HARRISON STREET: RECOMMENDATIONS ........................................... 17
ROADWAY SEGMENT FROM HARRISON STREET TO BLUE LAKES BOULEVARD.................................................... 19
ROADWAYISSUES ................................................................................................. 19
SEGMENT FROM HARRISON STREET TO BLUE LAKES BOULEVARD: RECOMMENDATIONS ........... 19
INTERSECTION OF FILER AVENUE AND BLUE LAKES BOULEVARD (US 93)........................................................20
INTERSECTION ISSUES ........................................................................................... 20
FILER AVENUE AND BLUE LAKES BOULEVARD (US 93): RECOMMENDATIONS ......................... 21
ROADWAY SEGMENT FROM BLUE LAKES BOULEVARD TO LOCUST STREET.........................................................23
ROADWAYISSUES ................................................................................................. 23
SEGMENT FROM BLUE LAKES BOULEVARD TO LOCUST STREET: RECOMMENDATIONS............... 23
INTERSECTION OF FILER AVENUE AND LOCUST STREET N................................................................................24
INTERSECTION ISSUES ........................................................................................... 24
FILER AVENUE AND LOCUST ST N: RECOMMENDATIONS .................................................. 26
TWIN FALLS HIGH SCHOOL FRONTAGE .............................................................................................................28
ROADWAYISSUES ................................................................................................. 28
TWIN FALLS HIGH SCHOOL FRONTAGE: RECOMMENDATIONS ............................................ 30
SEGMENT FROM TWIN FALLS HIGH SCHOOL TO EASTLAND DRIVE N.................................................................32
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ROADWAYISSUES ................................................................................................. 32
SEGMENT FROM TWIN FALLS HIGH SCHOOL TO EASTLAND DRIVE N: RECOMMENDATIONS........ 32
INTERSECTION OF FILER AVENUE AND EASTLAND DRIVE N..............................................................................33
INTERSECTION ISSUES ........................................................................................... 33
FILER AVENUE AND EASTLAND DRIVE N: RECOMMENDATIONS .......................................... 34
SUMMARY AND CONCLUSION............................................................................................................................35
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 3
LIST OF FIGURES
FIGURE 1: FILER AVENUE ROAD SAFETY AUDIT STUDY AREA.............................................8
FIGURE 2. TWIN FALLS FILER AVENUE RSA TEAM...........................................................9
FIGURE 3. RSA FINDINGS PRESENTATION .................................................................. 10
FIGURE 4: SPLIT PHASING FOR EASTBOUND/WESTBOUND APPROACHES............................. 11
FIGURE 5: MAST ARM SIGNS .................................................................................. 12
FIGURE 6: POTENTIAL LAYOUT FOR EASTBOUND/WESTBOUND APPROACHES AT FILER
AVE/WASHINGTON ST .......................................................................................... 13
FIGURE 7: UTILITY POLES IN SIDEWALKS.................................................................. 14
FIGURE 8: EXAMPLE BIKE LANES ............................................................................. 15
FIGURE 9: FILER AVE/HARRISON ST INTERSECTION ..................................................... 16
FIGURE 10: VEGETATION GROWTH CAN BLOCK DRIVER VIEW.......................................... 16
FIGURE 11: LADDER CROSSWALK MARKING STYLE ....................................................... 17
FIGURE 12: EXAMPLE STOP SIGNS WITH POST SLEEVES ................................................ 18
FIGURE 13: FIXED OBJECTS NEAR TRAVELED WAY ....................................................... 19
FIGURE 14: STARBUCKS DRIVEWAY ONTO FILER AVENUE ............................................... 20
FIGURE 15: TOUGH CURB WITH DELINEATORS ............................................................ 21
FIGURE 16: LEFT TURN SIGNAL SIGNING EXAMPLE ...................................................... 22
FIGURE 17: FILER AVENUE AND ELM STREET N ISSUES ................................................. 23
FIGURE 18: EXISTING LANE USE SIGN NEAR LOCUST STREET N INTERSECTION ................... 23
FIGURE 19: INTERSECTION SKEW AND MISALIGNMENT OF SOUTHBOUND SIGNAL HEADS........ 24
FIGURE 20. LOCUST ST SIGHT DISTANCE RESTRICTION IN NORTHWEST CORNER ................. 25
FIGURE 21: PERMISSIVE GREEN BALL LEFT TURN CONTROL............................................ 25
FIGURE 22: WESTBOUND APPROACH CHANNELIZATION AT LOCUST STREET N ...................... 26
FIGURE 23: EXAMPLE RIGHT TURN ARROW SIGNAL HEAD ............................................... 26
FIGURE 24: EXAMPLE LEFT TURN LANE CONTROL SIGN.................................................. 27
FIGURE 25: RECHANNELIZATION OF WESTBOUND APPROACH .......................................... 27
FIGURE 26: TWIN FALLS HIGH SCHOOL FRONTAGE ISSUES ............................................ 28
FIGURE 27: BUS LOADING ONLY SIGN NEAR DIAGONAL PARKING ..................................... 28
FIGURE 28: STUDENT WALKING IN ROADWAY ............................................................. 29
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FIGURE 29: STUDENTS CROSSING TO SEMINARY BUILDING ............................................ 29
FIGURE 30: WESTBOUND VEHICLE BACKUP IN THE MORNING WHEN SCHOOL STARTS ............ 30
FIGURE 31: POTENTIAL TREATMENTS NEAR TWIN FALLS HIGH SCHOOL ............................. 30
FIGURE 32: EXAMPLE PEDESTRIAN HYBRID BEACON ..................................................... 31
FIGURE 33 (LEFT): VEGETATION OVER THE ROADWAY ALONG FILER AVENUE ...................... 32
FIGURE 34 (RIGHT): LACK OF ADA RAMPS, FIXED OBJECT, AND UTILITY POLE BLOCKING
SIDEWALK......................................................................................................... 32
FIGURE 35: LIGHTING ON SOUTHERN AND WESTERN LEGS ............................................. 33
FIGURE 36. NORTHEAST SIDEWALK AND PEDESTRIAN CROSSING ..................................... 34
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EXECUTIVE SUMMARY J-A
The City of Twin Falls identified the Filer Avenue corridor between Washington Street N and
Eastland Drive N as a potential study area for a road safety audit (RSA), a process that considers
the safety of all road users, finds and reports on road safety issues, and identifies opportunities for
safety improvements. They were awarded funding for the RSA through the Local Highway Safety
Improvement Program (LHSIP) administered through the Local Highway Technical Assistance
Council (LHTAC).
Filer Avenue is an east/west collector that serves commercial, residential, and school oriented
traffic. Traffic volumes on Filer vary depending on location within the corridor. Filer has an Annual
Average Daily Traffic (AADT) of approximately 7,000 vehicles per day depending on location in the
corridor.
The RSA team noted many positives within the Flier Avenue corridor and want to recognize the
things the City of Twin Falls has done well.
• The corridor has quality signs that look well maintained.
• Pavement markings have been properly installed and are in good condition, including stop
bars at signalized intersection crosswalks, which is uncommon and is a significant safety
benefit.
• Most intersections have at least some lighting.
• Signal operations seem to be working for the traffic volumes at intersections.
• Vehicles are driving at appropriate operating speeds and the City's zone maintenance
program appears to be keeping the streets in pretty good shape.
Recommendations in this report are non-binding and require no commitments from the City or
other stakeholders. General recommendations for the corridor include:
• Fixed objects close to Filer Avenue are a safety risk if hit by drivers. They should be
reviewed for potential removal, relocation, or shielding.
• Stop signs at stop-controlled intersections could have retroreflective post sleeves installed
to improve visibility.
• Sight distance limitations were identified at several of the intersections. Property and/or
vegetation interfere with drivers' ability to see oncoming traffic. Adding painted stop bars at
the desired stop location (i.e., maximum sight distance for side street motorists) and
vegetation maintenance could mitigate this issue.
• Side streets at many of the unsignalized intersections cross over a steeper than optimal
grade at Filer Avenue. This causes drivers to proceed across Filer Avenue at very low speeds
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022
which increases the time they are exposed to mainline traffic within the intersection. Grade
improvements could improve this issue.
• To address misaligned signal heads and skewed intersection geometry, and to provide
additional information about proper lane use, near-side lane use control signs (in some
cases installed on the back on signal heads on mast arms) could be added.
• Sign heights should be verified or updated where needed to be a minimum of 7 feet from
the ground to the bottom of the sign.
• Access management and access management policy should be evaluated along the corridor.
Some access points are too close to intersections which leads to illegal left turning
movements across double-double yellow lines and/or left turns in heavy traffic.
• Some pedestrian crossing signs are missing accompanying diagonal down arrow plaques.
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 7
INTRODUCTION
The City of Twin Falls identified the Filer Avenue corridor between Washington Street N and
Eastland Drive N as a study area for this RSA. A typical RSA considers the safety of all road users,
qualitatively estimates and reports on road safety issues and opportunities for safety
improvements. The City then procured grant funding through the Local Highway Technical
Assistance Council (LHTAC) to proceed with the RSA. This report documents the findings of the RSA
and provides recommendations for improvements along the corridor. Recommendations in this
document are non-binding but serve as a guide for potential improvements the City of Twin Falls
could pursue. Figure 1 shows the RSA study area along Filer Avenue which has a 30 mph speed
limit except in the school zone around Twin Falls High School which has a 20 mph speed limit by
time of day.
Harrison A
Sa-
FiedMeyet tElementary
STUDY AREA 93
School
Twin Falls
Q STUDY INTERSECTION
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_ .
7 I ' LU ICU
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FIGURE 1: FILER AVENUE ROAD SAFETY AUDIT STUDY AREA
RSA PROCESS
The RSA process consists of eight steps per Federal Highway Administration (FHWA) guidance.
Those steps include:
1. Identify project or road in service to be audited
2. Select RSA team
3. Conduct a pre-audit meeting to review project information
4. Perform field observations under various conditions
5. Conduct audit analysis and prepare report of findings
6. Present audit findings to project owner/design team
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 8
7. Project owner/design team prepares formal response
8. Incorporate findings in the project when appropriate
The Filer Avenue RSA team (Figure 2) included local representatives as well as individuals from
outside of Twin Falls. The local team members brought their experience on the roadway which
provides useful background information on safety, operations, and the general feel of the corridor.
The outside representatives brought a fresh set of eyes to the corridor to identify issues that may
be missed by locals due to their familiarity with the area. The RSA team included the following
members:
• Two consultants (DKS Associates): Matt Ricks and Brian Chandler
• Representative of the Twin Falls Fire Department: Tim Lauda
• Representative of the Twin Falls Police Department: Lou Coronado
• Representative from LHTAC: Amanda LaMott
• Local FHWA representative: Lance Johnson
• City of Twin Falls Engineer: Erin Steel
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4
FIGURE 2. TWIN FALLS FILER AVENUE RSA TEAM
Team members (Left to Right): Tim Lauda, Lou Coronado, Brian Chandler, Amanda La Mott, Lance Johnson,
Erin Steel, and Matt Ricks
MHFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022
The RSA team met with City staff to complete the pre-RSA meeting and review project information
on November 8, 2021 at Twin Falls City Hall. DKS explained the RSA process and purpose to the
team and presented safety data. The team then reviewed the corridor and went over what to
expect for the field review and wrap-up meeting.
On November 9, 2021, the RSA team completed a field drive-through and walk-through of the
corridor. The team observed morning and evening traffic, school operations, intersection
operations, and made general observations of safety issues along the corridor.
On November 10, 2021, the RSA team presented s
the findings of the field review to City of Twin
Falls staff via an in-person meeting and
PowerPoint presentation (Figure 3). The �-
presentation highlighted what the City is
currently doing well, safety issues along the
corridor, and made recommendations for
improvements to the corridor.
The following sections present field observations,
photos, and a description of safety issues for the
intersections and roadway segments within the FIGURE 3. RSA FINDINGS PRESENTATION
study area. Also presented are potential remedies
for any identified safety issues.
The Filer Avenue corridor has had 179 crashes over the past five years (2016-2020) with 73
resulting in personal injury. There were no fatal crashes on the study corridor during the analysis
period.
The most common crash types and attributes included the following:
• 81% occurred at intersections
• 53% of crashes were angle or head-on-turning
• 23% of crashes were rear-end
22% occurred in dark, dusk, or dawn conditions
• 12% of crashes occurred on roads covered in water, ice, snow, or slush
7% involved a pedestrian or bicyclist
There were not common or obvious behavioral contributors (e.g., impaired driving, speeding,
inattention) identified in the crash report database.
meFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 10
The most common locations for crashes along the corridor occurred at these five intersections:
• Washington St - 25
• Blue Lakes Blvd - 25
• Locust St - 15
• Filmore St - 13
• Eastland Dr - 12
INTERSECTIONOF . WASHINGTON
INTERSECTION ISSUES
The intersection of Filer Avenue and Washington Street N currently operates with split signal
phasing for eastbound and westbound traffic (e.g., the entire eastbound approach [left, through,
and right vehicles] is green while the westbound approach is red and vice versa). Figure 4 shows
an example of the westbound signal heads which show a green indication, the eastbound signal
heads have a red indication.
A_
_J
s
_.—
FIGURE 4: SPLIT PHASING FOR EASTBOUND/WESTBOUND APPROACHES
If intersection geometry allows, intersections typically operate more effectively if split phasing is
not used since some movements from the eastbound and westbound approaches can proceed
concurrently.
In addition to the split phasing, the inner lane for the eastbound and westbound approaches is a
shared left and through movement. Since the movement is shared, the signal head gives an
indication for both movements. The left turn indication is a protected arrow while the through
MeFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 11
indication is a green ball (indicating a permitted movement). There could be some confusion from
drivers not knowing if they are allowed to complete a through movement since the indication also
shows a protected left turn. That confusion may have prompted some of the signs that are
currently on the mast arms telling drivers to "PROCEED ON GREEN". There is also a "RIGHT TURN
ON RED" sign on the mast arms at the intersection. Neither of these signs are typical messages for
regulatory signs. These signs are shown in Figure 5.
RIGHT
TURN
OCEEO ON
WO ON - RED
GREEN r
FIGURE 5: MAST ARM SIGNS
Some driveway access points are located near the intersection. The location of the access can be
an issue for left turning vehicles into the driveway and left turning vehicles from the driveways due
to intersection queues or vehicles traveling along streets.
Intersection approaches on Filer Avenue widen to two lanes in each direction just before the
intersection. After a vehicle proceeds through the intersection, these two lanes quickly drop to one,
forcing vehicles to merge into the single remaining lane. This causes additional merging
movements for vehicles which can lead to vehicle conflicts. Some drivers may avoid the merge by
driving in the through/left lane, causing lane imbalances which can be detrimental to operations.
FILER AVENUE AND WASHINGTON STREET N: RECOMMENDATIONS
The RSA team recommends City staff remove signage like "RIGHT TURN ON RED" and "PROCEED
ON GREEN" as they upgrade intersection infrastructure. Those signs could be removed when this
intersection is upgraded in the near future since the City was awarded a Federal-Aid Urban funding
grant. The split phasing should also be removed if the geometry of the intersection allows.
As part of the intersection upgrade, the number of approach lanes and pockets should undergo a
traffic analysis to determine needed pocket lengths and lane assignment. A potential layout could
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 12
be a left turn pocket and a through/right lane for the eastbound and westbound approaches as
shown in Figure 6. Adding a left turn lane can reduce injury crashes at an intersection by 25-43%.1
Having a single through lane would remove the need for the receiving lane that drops on the far
side of the intersection, removing the need for vehicles to merge after going through the
intersection. This will be analyzed as part of the intersection design of the Federal-Aid Urban
project.
Washington St N
Filer Ave
FIGURE 6: POTENTIAL LAYOUT FOR EASTBOUND/WESTBOUND APPROACHES AT FILER
AVE/WASHINGTON ST
ROADWAYR• M WASHINGTON STREET N TO HARRISON
ROADWAY ISSUES
This section of roadway typically has sidewalk on the north side of the street only. This sidewalk
has utility poles which block most of the walkable area as shown in Figure 7 on the next page.
There is also a general lack of American Disability Act (ADA) ramps for eastbound and westbound
pedestrians who walk along Flier Avenue, crossing the side streets.
' FHWA CMF Clearinghouse ID 444. Srinivasan, R., B. Lan, and D. Carter. Report No. FHWA/NC/2013-11. North Carolina
Department of Transportation. Raleigh, North Carolina. (October 2014).
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 13
�11
FIGURE 7: UTILITY POLES IN SIDEWALKS
There are street lighting gaps noticeable during dark conditions. Unsignalized intersections typically
have at least one street light but the uniformity of lighting between those intersections is poor.
More uniform light can make pedestrians feel safer on sidewalks, provide better visibility for
drivers, and deter crime.
There are currently no pedestrian crossings between the north and south sides of the street. Since
the distance between Washington Street N and Harrison Street is about 1/2 mile, some pedestrians
may be crossing without a marked crosswalk in this section.
The corridor also has some fixed objects near the traveled way on Filer Avenue. Some of these
objects are concrete which, if hit by a vehicle, could cause injuries.
SEGMENT FROM WASHINGTON STREET N TO HARRISON STREET:
RECOMMENDATIONS
Sidewalk could be added on the south side of Filer Avenue. If a major project occurs on the
corridor, utility poles could be moved or lines could be moved underground so existing sidewalks
are not blocked. In addition to adding sidewalk, additional pedestrian crossings of Filer Avenue
could be added between Washington Street N and Harrison Street. The additional crossings would
improve connectivity of the street network for pedestrians, and installing high-visibility crosswalks
can reduce vehicle pedestrian crashes by 40%.2
z FHWA CMF Clearinghouse ID 280. Chen, L., C. Chen, and R. Ewing. "The Relative Effectiveness of Pedestrian Safety
Countermeasures at Urban Intersections - Lessons from a New York City Experience." Washington, DC, 2012.
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 14
This area has roadway width to implement other improvements like bike lanes (Figure 8) or a road
diet. The type of bike lanes would need to be determined through the City's Bicycle Master Plan
and community feedback. In similar existing conditions, the addition of bicycle lanes has shown an
overall reduction in all crashes of 21% by calming vehicle traffic and providing bicyclists with a
designated lane for travel.3
If bike lanes are not desired on this roadway, sidewalks could be extended into the traveled way as
an option instead of needing to squire right-of-way from property owners or move utility poles.
FIGURE 8: EXAMPLE BIKE LANES
Fixed objects near the roadway should be removed, relocated, or shielded where feasible.
Removing or relocating fixed objects outside the clear zone can reduce all crashes by 38%.4
Street lighting should be assessed to verify proper lighting levels and uniformity. Research shows a
functional relationship (i.e., a mathematical formula) of crash reduction depending on existing
illuminance.5 For example, increasing luminance from low (< 0.2 fc) to medium (>_ 0.2 fc and <1.1
fc) showed a reduction in nighttime crashes of 52%.6
s FHWA CMF Clearinghouse ID 618. Avelar, R., K. Dixon, S. Ashraf, A, Jhamb, and B. Dadashova. "Development of Crash
Modification Factors for Bicycle Lane Additions While Reducing Lane and Shoulder Widths" Report No. FHWA-HRT-21-013.
Federal Highway Administration, Office of Safety Research and Development. McLean, Virginia. (2021).
4 FHWA CMF Clearinghouse ID 72. Hovey, P. W. and Chowdhury, M., "Development of Crash Reduction Factors." 14801(0),
Ohio Department of Transportation, (2005)
s FHWA CMF Clearinghouse ID 490. Wang, Z., P. Lin, Y. Chen, P. Hsu, S. Ozkul, and M. Bato. "Safety Effects of Street
Illuminance on Roadway Segments in Florida". Presented at the 96th Annual Meeting of the Transportation Research
Board, Paper No. 17-05438, Washington, D.C., (2017).
6 FHWA CMF Clearinghouse ID 462. Wang, Z, F. Wei, P. S. Lin, P. P. Hsu, S. Ozkul, J. Jackman, and M. Bato. "Safety Effects
of Street Illuminance at Urban Signalized Intersections in Florida," Presented at the 96th Annual Meeting of the
Transportation Research Board, Paper No. 16-6376, Washington, D.C., (2017).
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 is
INTERSECTIONOF . HARRISON
INTERSECTION ISSUES
This intersection is currently all-way stop controlled with a static flashing red beacon on span wires
over the intersection. General understanding of best practices in traffic safety indicated that static
flashers do not provide a safety benefit or disbenefit. The RSA team observed pedestrians and
bicyclists traveling through the intersection (Figure 9). The intersection serves as a connection
between residents and the nearby Harrison Elementary School.
The pavement currently —s
has rutting issues on
Filer. Additionally, this
intersection has
pavement rutting and
grades from the crown of
the pavement to storm
gutters the cause
northbound and
southbound traffic to
proceed slowly through _
the intersection. _.
Some pedestrian curb
ramps are missing and FIGURE 9: FILER AVE/HARRISON ST INTERSECTION
there is only one street
light at the intersection which does not light up all quadrants. Vegetation at the intersection can
block driver vision when looking for gaps to proceed through the intersection (Figure 10).
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1
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FIGURE 10: VEGETATION GROWTH CAN BLOCK DRIVER VIEW
BEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 16
FILER AVENUE AND HARRISON STREET: RECOMMENDATIONS
Replace overhead static flasher with RRFB. Overhead intersection flashers that operate in
"static" mode (i.e., the lights flash all the time, not in relation to an input) have not been shown to
improve roadway safety. A recent TTI report stated, "overhead flashing beacons do not greatly
affect the occurrence of crashes positively or negatively."'
There is some anecdotal evidence that shifting driver attention from the roadway itself to the
flasher overhead could distract them from other road users. The RSA team recommends removing
this flasher or replacing with a Rectangular Rapid Flashing Beacon (RRFB) treatment to support
pedestrian and bicyclists crossing Flier Avenue to and from school. RRFBs have been shown to
reduce pedestrian-involved crashes by 47%.8
Improve crosswalk markings near schools. The ,!
crosswalks are currently marked, but ladder crossing
markings could improve visibility and longevity of the r - -
crosswalk paint. The ladder markings can be aligned
in such a way that vehicle tire avoid driving over the
paint which reduces wear on the paint markings.
Figure 11 shows an example of a ladder crosswalk
marking, which can reduce pedestrian-related crashes
by 40%.9
Pilot Installations, The RSA team
recommends pilot installations of ladder-style FIGURE 11: LADDER CROSSWALK
markings at crosswalks near schools, then MARKING STYLE
assessing the benefits to determine if citywide
implementation is appropriate.
Improve pavement conditions. To address pavement rutting at the intersection, the City should
consider pavement treatment to remove the rutting and provide a smoother, higher-friction surface
for motorists.
'Geedipally, Srinivas, et al,"Safety Effectiveness of Intersection Center-mounted Overhead Flashing Beacons,"Texas DOT
IAC 58-OXXIAOOI: Safety Analysis in Support of Traffic Operations,Texas A&M Transportation Institute, College Station,
TX, 2020
s FHWA CMF Clearinghouse ID 487. Zegeer, C., et al, "Development of Crash Modification Factors for Uncontrolled
Pedestrian Crossing Treatments", National Cooperative Highway Research Program, Research Report 841, Washington,
D.C., 2017.
9 FHWA CMF Clearinghouse ID 280. Chen, L., C. Chen, and R. Ewing. "The Relative Effectiveness of Pedestrian Safety
Countermeasures at Urban Intersections - Lessons from a New York City Experience." Presented at the 91st Annual
Meeting of the Transportation Research Board, January 22-26, Washington, DC, 2012.
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 17
ADA curb ramp improvements should be considered. Street lighting should be analyzed and
improved so all quadrants of the intersection have sufficient light (12% reduction in nighttime
crashes).10 Vegetation should be trimmed and maintained so it does not block drivers from seeing
pedestrians, bicyclists, or other vehicles. Stop bar paint markings should be maintained or installed
where missing.
Pavement maintenance is needed to repair rutting and address the grade issues across the
intersection.
Since this location is close to an elementary school, a crossing guard may be considered and
coordinated with the school (the school district typically provides crossing guards). Further study
may be warranted to determine the level of pedestrian and bicycle use due to the elementary
school.
Additionally, the stop signs could be fitted with reflective post sleeves. These sleeves (shown in
Figure 12) are relatively inexpensive and increase the visibility of the signs in both daylight and at
night. These could be piloted on Filer 7 -
Avenue and then expanded to other parts AIR POR
of the City.
• Pilot Implementation, While the
retroreflective post sleeve treatment STOP
is introduced at this all-way stop-
controlled intersection, the RSA
team recommends installing this at
2-way stop-controlled intersections
along Filer Avenue as an initial pilot.
After a review period to assess any
installation, maintenance issues,
and general feedback on benefits,
the City should consider broader
implementation along Filer Avenue
and other roads.
In
FIGURE 12: EXAMPLE STOP SIGNS WITH POST
SLEEVES
10 FHWA CMF Clearinghouse ID 163. Donnell, E.T., R.J. Porter, and V.N. Shankar. "A Framework for Estimating the Safety
Effects of Roadway Lighting at Intersections." Safety Science, Vol. 48(10), pp. 1436-1444, 2010.
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ROADWAY SEGMENT FROMHARRISON • BLUE LAKES BOULEVARD
ROADWAY ISSUES
This roadway segment has some of the same issues as the segment between Washington Street N
and Harrison Street. There are gaps in the sidewalk, street lighting gaps, and fixed objects near the
traveled way (Figure 13). Fixed object crashes do not appear to be a significant issue in the crash
data, but their proximity to Filer Avenue is still a safety concern to consider.
•. -
_,. -- 1
FIGURE 13: FIXED OBJECTS NEAR TRAVELED WAY
At the Fillmore Street intersection, there is crosswalk with no ramps. This intersection also has
pavement rutting and steep grades from the crown of the pavement to storm gutters the cause
northbound and southbound traffic to proceed slowly through the intersection. Grade issues at side
streets are not uncommon for a large portion of Filer Avenue.
SEGMENT FROM HARRISON STREET TO BLUE LAKES BOULEVARD:
RECOMMENDATIONS
Gaps in sidewalks should be filled in. Fixed objects should be removed, relocated, or shielded (38%
crash reduction)."
Street lighting should be analyzed and improved to reach an adequate lighting level and uniformity
(52% reduction in nighttime crashes),I2
The intersection of Filer Avenue and Fillmore Street should have ADA ramps installed. Rutting and
grading issues should also be addressed.
11 FHWA CMF Clearinghouse ID 72. Hovey, P. W. and Chowdhury, M., "Development of Crash Reduction Factors." 14801(0),
Ohio Department of Transportation, (2005)
12 FHWA CMF Clearinghouse ID 462. Wang, Z, F. Wei, P. S. Lin, P. P. Hsu, S. Ozkul, J. Jackman, and M. Bato. "Safety Effects
of Street Illuminance at Urban Signalized Intersections in Florida," Presented at the 96th Annual Meeting of the
Transportation Research Board, Paper No. 16-6376, Washington, D.C., (2017).
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 19
INTERSECTIONOF • R.
INTERSECTION ISSUES
The operation of this intersection is shared by ITD and the City of Twin Falls. ITD maintains the
pavement. Since both agencies play a role in the performance of the intersection, quality
coordination between the two agencies is needed to maintain pavement, update signal timing, or
make modifications to other intersection infrastructure. Having both agencies involved with the
operation and maintenance can cause delays to improvements.
This intersection has nearby access issues which can lead to risky left turn movements to and from
both Filer Avenue and Blue Lakes Boulevard (e.g., gas station driveways, Starbucks driveway onto
Filer Avenue). The Starbucks driveway roadway paint lines are a double-double yellow line which is
meant to restrict vehicles from crossing it (see Figure 14). Drivers still make the left turn out of the
Starbucks parking lot across the restrictive paint lines.
3
FIGURE 14: STARBUCKS DRIVEWAY ONTO FILER AVENUE
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 20
This is a heavily traveled intersection that experiences left turn conflicts and has a history of
related crashes. Some of the signal heads are misaligned over their respective lanes. The RSA
team also identified a streetlight out on the northwest corner during their evening field review
Crosswalk paint markings were faded, as seen in Figure 14 above, and there is pavement rutting
on Blue Lakes Boulevard.
FILER AVENUE AND BLUE LAKES BOULEVARD (US 93): RECOMMENDATIONS
For access management, tough curb with delineators could be installed to help prevent drivers
making restricted or undesirable left turns. The curb/delineators could be installed on the
westbound approach and the southbound approach which have the most apparent access issues
near the intersection. Delineators by themselves are often not enough of an impediment to making
restricted left turns and can be run over by drivers. The addition of tough curb is generally
sufficient to discourage drivers from running over the delineators. An example of tough curb with
delineators is shown in Figure 15.
I
x
FIGURE 15: TOUGH CURB WITH DELINEATORS
The intersection currently has permissive flashing yellow arrow and protected green arrow
operations for each approach to the intersection. During times of heavy traffic or by time of day,
the permissive left turns could be "turned off' and only protected green arrow turns allowed. This
would limit left turn and through movement interactions; this reduces left-turn crashes by 99%
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 21
during the times the signal operates in protected-only mode.13 Traffic analysis would be needed to
verify an acceptable level of operations could be achieved with protected-only left turn operations.
Northbound and southbound left turn stop bars on Blue Lakes Boulevard could also be shifted back
a few feet to give left turners from Filer Avenue onto Blue Lakes Boulevard an easier turning
radius.
Misaligned northbound signal heads on Blue Lakes Boulevard should be realigned and centered
over their respective lanes. Crosswalk markings should be repainted and rutting issues addressed
in the pavement. Ladder crosswalks could be considered at this intersection as well (40% reduction
in pedestrian-related crashes).14 Maintenance of this intersection should be coordinated between
ITD and the City.
Additional signing on mast arms giving drivers information about left turns could also be provided
at this intersection. An example sign is shown in Figure 16.
A separate RSA along Falls Avenue may need to be coordinated with ITD and the City to review
safety needs and potential improvements along the ITD corridor.
LEFT
TURN
SIGNAL
FIGURE 16: LEFT TURN SIGNAL SIGNING EXAMPLE
13 FHWA CMF Clearinghouse ID 22. Harkey, D.L., et al. NCHRP Report 617: Accident Modification Factors for Traffic
Engineering and ITS Improvements, NCHRP, Transportation Research Board, Washington, DC, 2008.
14 FHWA CMF Clearinghouse ID 280. Chen, L., C. Chen, and R. Ewing. "The Relative Effectiveness of Pedestrian Safety
Countermeasures at Urban Intersections - Lessons from a New York City Experience." Presented at the 91st Annual
Meeting of the Transportation Research Board, January 22-26, Washington, DC, 2012.
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 22
ROADWAY SEGMENT FROMBOULEVARD • LOCUST
ROADWAY ISSUES
This stretch of roadway has similar access management issues to some of the roadway segments
already discussed with access points located too close to intersections. At the Filer Avenue and Elm
Street N intersection, the stop sign for northbound Elm Street drivers is too short. The pedestrian
crossing across Filer Avenue does not have a curb ramp on the north side of Filer. The double-
double yellow line paint markings on Filer near Elm Street are striped too far into the intersection,
making an eastbound left turn into the commercial driveway an illegal movement. Figure 17 below
highlights these issues.
FIGURE 17: FILER AVENUE AND ELM STREET N ISSUES
Approaching the intersection of Filer Avenue and Locust Street N, the eastbound inner (left-most)
lane turns into a left turn only lane without sufficient warning for motorists. This change can cause
drivers to merge to the right lane late to continue through at Locust Street N, which may result in
sideswipe conflicts.
SEGMENT FROM BLUE LAKES BOULEVARD TO LOCUST STREET: RECOMMENDATIONS
Access management should be considered along this stretch to prevent
unwanted movements from driveways near intersections. The double-
double yellow line near Elm Street N could be ground off and repainted so
it does not protrude into the intersection. An ADA ramp could be installed
at Elm Street N on the north side of Filer Avenue. The stop sign for Elm
Street N should also be raised to meet City and other applicable ONLY
standards.
For the eastbound approach to Locust Street N, there is an existing lane FIGURE 1S:
EXISTING LANE USE
use sign near the intersection (Figure 18). A similar sign should be placed SIGN NEAR LOCUST
farther west in advance of where the solid white lane line begins. The sign STREET N
could be placed near the New Covenant United Reformed Church access or INTERSECTION
BeFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 23
closer to Elm Street N. The roadway east of Elm Street N could be rechannelized to force drivers to
merge right into a single travel lane near the New Covenant United Reformed Church access. This
is a more expected driving pattern for approaching motorists, and then a left turn pocket at Locust
Street N could be striped.
INTERSECTION OF FILER AVENUE AND LOCUST STREET N A
INTERSECTION ISSUES
The intersection of Filer Avenue and Locust Street N has a skew issue (misalignment of the
intersection legs) on the northbound and southbound approaches. This requires drivers to not
follow a straight path through the intersection which can result in some confusion on proper lane
use. The southbound signal heads are not aligned over the southbound approach lanes (Figure 19).
The misalignment of the signal heads can cause southbound drivers approaching the intersection to
no know which lane is the through lane for the intersection (the through signal head location
makes the right turn pocket seem like the through lane).
Lt
f i
FIGURE 19: INTERSECTION SKEW AND MISALIGNMENT OF SOUTHBOUND SIGNAL HEADS
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 24
The sight distance for the eastbound and westbound right turn movements is insufficient. This is
due to the property on the southeast quadrant of the intersection for the westbound approach, the
property and vegetation on the northwest quadrant for the eastbound approach (see Figure 20),
and partially to the intersection skew. The eastbound right turn on red is restricted due to the poor
sight distance.
,a
90,
FIGURE 20. LOCUST ST SIGHT DISTANCE RESTRICTION IN NORTHWEST CORNER
The eastbound and westbound left turn are controlled by permissive green balls (Figure 21). These
are less effective than flashing yellow arrow control. The northeast corner streetlight was out at the
time of the RSA field visit.
oryS.
' �YiEy . •
j
FIGURE 21: PERMISSIVE GREEN BALL LEFT TURN CONTROL
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 25
The westbound approach channelization directs drivers into the rightmost through lane (there are
two through lanes and a left turn pocket on this approach). Since drivers are directed by upstream
channelization to the right through lane, there is a large shift for left-turning drivers to enter the
left turn pocket, which makes the taper length feel insufficient (Figure 22).
ww
k
L ,
�k
FIGURE 22: WESTBOUND APPROACH CHANNELIZATION AT LOCUST STREET N
FILER AVENUE AND LOCUST ST N: RECOMMENDATIONS
Ultimately, the sight distance for the westbound and
eastbound right turns should be improved by lowering
fencing in the drivers' line of sight, trimming and
maintaining vegetation, and/or managing property
blockage of sight at the intersection (injury crash
reduction of 48%).15 Another solution could be
installing right turn arrows to restrict right turns on
red until the sight distance issues can be addressed TURN
RED -
(Figure 23). Green ball indications for left turns at the ON N RED
ARROW
intersection could be replaced with flashing yellow
arrow signal heads, reducing crashes by n '�
approximately 50%.16 FIGURE 23: EXAMPLE RIGHT TURN
ARROW SIGNAL HEAD
is FHWA CMF Clearinghouse Study ID 14. Elvik, R. and Vaa,T., "Handbook of Road Safety Measures." Oxford, United
Kingdom, Elsevier, (2004)
is FHWA CMF Clearinghouse Study ID 422. Simpson, C.L. and S.A. Troy. "Safety Effectiveness of Flashing Yellow Arrow:
Evaluation of 222 Signalized Intersections in North Carolina". Presented at the 94th Annual Meeting of the Transportation
Research Board, Paper No. 15-1593, Washington, D.C., (2015).
MEFILER AVENUE ROAD SAFETY AUDIT - ROAD SAFETY AUDIT REPORT - FEBRUARY 2022 26
The misaligned heads for the southbound approach would require a new mast arm and likely a new
pole to get the heads centered over their lanes. Additional signing could be a temporary mitigation
that does not require replacing the pole. A lane control sign could be installed for the southbound
left turn on the back of the mast arm behind the signal head (Figure 24).
ONLY
SIT
FIGURE 24: EXAMPLE LEFT TURN LANE CONTROL SIGN
The westbound approach could be rechannelized to direct drivers into the inner through lane. Then
the shift to the left turn pocket or the curbside through lane would not be as dramatic. Existing
taper lengths could likely be maintained with this change (see Figure 25).
i �
71
ifier Me
00
MI-A IF-
M.4- T
:�.
FIGURE 25: RECHANNELIZATION OF WESTBOUND APPROACH
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 27
TWIN FALLS HIGH
ROADWAY ISSUES
The parking area on the northside of Filer Avenue near Twin Falls high school has several issues
that may confuse drivers. Starting near Locust Street N, there is an access very close to the
intersection. There is a bus loading only sign just east of the diagonal parking. Old diagonal parking
lines can still be seen in the bus loading zone east of the current diagonal parking (see Figure 26);
this sends a confusing message, since parking appears to be allowed beyond that sign in the lot to
the west. Figure 26 shows these issues on an aerial.
Buses unload in their designated area and have a sharp skew which affects their ability to see
traffic when they leave the parking lot (also shown in Figure 27). This parking area and the campus
exit just east of it are restricted to right turn only by a sign. That restriction is frequently ignored
by drivers.
.
i loading �• �. �~
MAIN I
o
T'
FIGURE 26: TWIN FALLS HIGH SCHOOL FRONTAGE ISSUES
BUS
LOADING
ONLY .-
ex
it here
FIGURE 27: BUS LOADING ONLY SIGN NEAR DIAGONAL PARKING
MHFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 28
The southside of the roadway lacks sidewalks and the RSA team saw several students walking in
the roadway (see Figure 28). While observing traffic before the beginning of school, the RSA team
saw drivers stop at the midblock crosswalk to yield for pedestrians and drop off student who exited
the left side of the car in the middle of the roadway.
FIGURE 28: STUDENT WALKING IN ROADWAY
The midblock crosswalk is very busy before school, after school, and every time classes change
since students walk to and from the seminary building located south of Filer Avenue. The existing
LED signs require a push-button for activation, which students rarely used during the team's
observation (Figure 29). 17 When students cross the street, they typically do so as individuals or in
small groups. The spacing of the groups does not allow vehicles to proceed since they must yield
for pedestrians. This caused traffic to backup, especially in the morning period. The RSA team
observed backup of 10 or more vehicles during the before-school drop-off time period.
z I
Ae
FIGURE 29: STUDENTS CROSSING TO SEMINARY BUILDING
17 The team also experienced the push button working intermittently. Sometimes pushing it turned on the LEDs, but other
times it did not.
MFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 29
Figure 30 shows westbound vehicles backed up from the crosswalk past Madrona Street in the
morning when school is starting. The queuing on the street can be a safety issue that leads to rear
end crashes and the aforementioned students exiting vehicles along Filer Avenue, sometimes out
the left side of the vehicle in the middle of the street.
.� A �s s
4
FIGURE 30: WESTBOUND VEHICLE BACKUP IN THE MORNING WHEN SCHOOL STARTS
TWIN FALLS HIGH SCHOOL FRONTAGE: RECOMMENDATIONS
Figure 31 provides a summary of RSA team recommendations at and near Twin Falls High School.
ALLOW ACCESS TO MOVE"DO NOT ENTERI
MAIN PARKING LOT CLARIFY PAVEMENT BUS LOADING ONLY"
MARKING FOR BUS ONLY SIGN BEFORE THE
CLOSE BUS LOADING ZONE
ACCESS
• 0
ADD REPLACE RRFB
SIDEWALK J
WITH PEDESTRIAN
HYBRID BEACON
•
FIGURE 31: POTENTIAL TREATMENTS NEAR TWIN FALLS HIGH SCHOOL
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 30
The access management strategy for the diagonal parking lot next to Filer Avenue should be
reviewed. Left turns out of the parking lot could be restricted during peak times and allowed at
other times of the day. Additional signing informing drivers to not make those left turns could be
installed. For the access point east of the bus drop off, a concrete median that does not allow
southbound left turns could be installed. Improved bus drop-off signing should be considered to
make the bus loading zone clear. The diagonal parking lines that can be seen in the bus loading
zone should be removed.
The west-most driveway access from the parking lot that is very close to Locust Street N should be
closed, which would require a change to the parking lot to allow vehicles in the curbside parking
area to enter the larger parking lot before exiting the school property.
Sidewalks should be added on the south
side of Filer Avenue to reduce the frequency �+ rUND(R8I10MS
SIO� (ROSSM►1l
of students walking in the roadway, which �o
can reduce the risk of pedestrian-vehicle
crashes resulting in fatalities or serious
injuries by 59%.18 A pedestrian hybrid
beacon (PHB) should be considered for the
r•
crosswalk (see Figure 32). The beacon will ;� .. ., ..
provide a few advantages over the currentif
•
crossing:
• A PHB crossing will be more visibly
marked to increase conspicuity for -
pedestrians crossing the road, and
FIGURE 32: EXAMPLE PEDESTRIAN HYBRID
PHBs have been shown to reduce BEACON
vehicle-pedestrian crashes by 56%.19
• A PHB can be timed more like a traffic signal. It will help clump students together in groups
when they cross, which will provide gaps for vehicles to proceed along Filer Avenue. The
queue shown in Figure 30 will be less likely to form. The school and seminary could
coordinate on training for the students on how the use the crossing.
• This location would likely qualify for an LHTAC grant to install the beacon since it provides
access to high school facilities and would likely also serve the nearby elementary school.
18 FHWA CMF Clearinghouse Study ID 515. Alluri, Priyanka, et al. "Statewide Analysis of Bicycle Crashes." Florida
Department of Transportation (May 2017).
is FHWA CMF Clearinghouse Study ID 487. Zegeer, C., et al. "Development of Crash Modification Factors for Uncontrolled
Pedestrian Crossing Treatments", National Cooperative Highway Research Program, Research Report 841, Washington,
D.C., 2017.
MHFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 31
SEGMENT FROM TWIN FALLS HIGH SCHOOLTO EASTLAND DRIVE
ROADWAY ISSUES
This section of Filer Avenue had minimal issues. The traveled way is wide here so there is potential
for higher speeds, but the RSA team did not observe higher speeds from drivers in this section.
Vegetation is overgrowing the roadway/sidewalks in a few places on the north side of Filer Avenue
(Figure 33). On the south side, ADA ramps do not exist for side street crossings, the utility poles
and irrigation boxes are close to the road and could be fixed objects for motorists who depart the
roadway (see Figure 34) Some utility poles also block sidewalk access.
kIL
FIGURE 33 (LEFT): VEGETATION OVER THE ROADWAY ALONG FILER AVENUE
FIGURE 34 (RIGHT): LACK OF ADA RAMPS, FIXED OBJECT, AND UTILITY POLE BLOCKING
SIDEWALK
SEGMENT FROM TWIN FALLS HIGH SCHOOL TO EASTLAND DRIVE N:
RECOMMENDATIONS
Speed feedback signs could be installed to inform drivers if they are speeding. These would be
more beneficial in the westbound direction as they approach Twin Falls high school. Vegetation
should be maintained and controlled so it does not interfere with roadway users. On the south side,
consider reducing the height of the irrigation boxes to reduce the impact of a vehicle striking the
structure. Move the utility poles or widen the sidewalks toward the street to provide better
pedestrian access and reduce the risk of a fixed object crash (removing or relocating fixed objects
outside the clear zone can reduce all crashes by 38%).20
21 FHWA CMF Clearinghouse ID 72. Hovey, P. W. and Chowdhury, M., "Development of Crash Reduction Factors." 14801(0),
Ohio Department of Transportation, (2005)
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 32
Retrofit the pedestrian crossings with ADA curb ramps for both directions (north-south and east-
west).
There is adequate cross section to consider bicycle lanes, additional pedestrian treatments (e.g.,
wider sidewalks, median pedestrian refuge islands), and/or a road diet (i.e., reconfiguration of
lanes, lane width reduction). Bicycle lanes can provide an overall reduction in all crashes of 21% by
calming vehicle traffic and providing bicyclists with a designated lane for travel.21
INTERSECTIONOF . EASTLAND DRIVE
INTERSECTION ISSUES
This intersection had relatively few issues. There is lighting on only two of the intersection legs
(Figure 35). There are "No Parking" signs near the intersection on some approaches but not all.
�I
-' --. �
FIGURE 35: LIGHTING ON SOUTHERN AND WESTERN LEGS
21 FHWA CMF Clearinghouse ID 618. Avelar, R., K. Dixon, S. Ashraf, A, Jhamb, and B. Dadashova. "Development of Crash
Modification Factors for Bicycle Lane Additions While Reducing Lane and Shoulder Widths" Report No. FHWA-HRT-21-013.
Federal Highway Administration, Office of Safety Research and Development. McLean, Virginia. (2021).
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 33
The northeast corner was designed for future widening which results in a long pedestrian crossing
and a "catch spot" for debris (Figure 36).
WA
) )
- �i
FIGURE 36. NORTHEAST SIDEWALK AND PEDESTRIAN CROSSING
FILER AVENUE AND EASTLAND DRIVE N: RECOMMENDATIONS
Street lighting could be improved with luminaires installed on all approaches. Ladder crosswalks
could be installed here as well. Research shows a functional relationship (i.e., a mathematical
formula) of crash reduction depending on existing illuminance.22 For example, increasing luminance
from low (< 0.2 fc) to medium (>_ 0.2 fc and <1.1 fc) showed a reduction in nighttime crashes of
52%.23
The northeast corner could be modified to reduce the length of the crossing which could reduce
pedestrian exposure and improve signal operations. Since the curb line was designed with future
widening in mind, this change could be made with pavement marking and delineation.
22 FHWA CMF Clearinghouse ID 490. Wang, Z., P. Lin, Y. Chen, P. Hsu, S. Ozkul, and M. Bato. "Safety Effects of Street
Illuminance on Roadway Segments in Florida". Presented at the 96th Annual Meeting of the Transportation Research
Board, Paper No. 17-05438, Washington, D.C., (2017).
23 FHWA CMF Clearinghouse ID 462. Wang, Z, F. Wei, P. S. Lin, P. P. Hsu, S. Ozkul, J. Jackman, and M. Bato. "Safety Effects
of Street Illuminance at Urban Signalized Intersections in Florida," Presented at the 96th Annual Meeting of the
Transportation Research Board, Paper No. 16-6376, Washington, D.C., (2017).
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 34
SUMMARY AND CONCLUSION
The RSA team identified many positive operational and safety-related aspects along the Filer
Avenue corridor. The City has installed quality signs that look well maintained. Pavement markings
have been properly installed and are in good condition, including stop bars at signalized
intersection crosswalks, which provide a safety benefit to pedestrians. Most intersections have at
least some lighting. Signal operations seem to be working for the traffic volumes at each signalized
intersection. Vehicles are driving at appropriate operating speeds and the City's zone maintenance
program appears to be keeping the streets in pretty good shape.
Recommendations in this report are non-binding and require no commitments from the City or
other stakeholders. General recommendations for the corridor include the following in three priority
categories (High, Medium, and Low) based on each treatments potential to reduce the frequency
and severity of future crashes. Prioritization also considers cost and feasibility (e.g., moving utility
poles) to some degree, but the primary criterion is effectiveness at improving safety.
High Priority
• Washington Street N Intersection. Remove extraneous signing and modify Filer
Avenue's eastbound and westbound lane configurations.
• Sidewalk In-fill. Add sidewalk along Filer Avenue to accommodate pedestrians at the
following segments:
o From Washington Street N to Harrison Street
o In front of the High School
• High-Visibility Crosswalks. Install ladder-style crosswalks and stop bars (where
appropriate) at pedestrian crossings, starting with locations near schools (high school
frontage, Harrison St crossing).
• Stop Sign Retroreflective Post Sleeves. Post sleeves and increase the visibility of the
signs in both daylight and at night. Start with 2-way stop locations along Filer Avenue.
o Fixed Object Removal, Relocation, and Modification. Those that are reasonable
to move or relocated should be reviewed for potential removal, relocation, or
shielding. Examples include removing vegetation, modifying irrigation boxes.
• Blue Lakes Boulevard to Locust Street
o Restripe the "double-double-yellow" in this segment for eastbound left-turn
movements.
o Improve eastbound signing and channelization to support road users approaching
Locust Street.
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 35
• Filer Avenue and Locust Street Signalized Intersection
o Improve intersection sight distance.
o Modify left-turn signals from green ball to flashing yellow arrow. Consider a
protected-permissive left turn.
o Add lane use control signing
o Rechannelize pavement marking for westbound road users.
• High School Frontage. Replace the current RRFB with a Pedestrian Hybrid Beacon and add
sidewalk in-fill on the south side of Filer Avenue.
Medium Priority
• Assess Lighting. Conduct a street lighting assessment to verify proper lighting levels and
uniformity, and then install luminaire in-fill as appropriate.
• New Pedestrian Crossings. Add new pedestrian crossings at appropriate locations (e.g.,
segment between Washington Street N and Harrison Street)
• ADA Improvements. Install ADA-approved curb ramps at every currently-marked
pedestrian crossing and any new crossings.
• Pavement Condition Improvements. To address pavement rutting at several
intersections, consider pavement treatment to remove the rutting and provide a smoother,
higher-friction surface for motorists.
• Access Management.
o Blue Lakes Boulevard Intersection; Install tough curb and delineators west of the
intersection on Filer Avenue (near the Starbuck's).
o Segment from Blue Lakes Boulevard to Locust Street. Manage access to
driveways along this segment
• Filer Avenue and Harrison Street: Replace overhead flasher with an RRFB, clear
vegetation, and install improved intersection lighting.
• High School Frontage. Modify pavement marking and signing for bus loading and parking.
Close access nearest the Locust Street N intersection.
MEFILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 36
Low Priority
• Other Fixed Objects. More difficult-to move fixed objects, like utility poles, should be
considered for relocation as part of major projects in the future.
• Bicycle Lanes. Consider bicycle facilities consistent with the City's Bicycle Master Plan and
community feedback. For example, the segment between the high school and Eastland
Drive N has adequate width to consider bicycle lanes.
• Blue Lakes Boulevard Signal. Coordinate with ITD regarding signalized intersection
recommendations at Filer Avenue and Blue Lakes Boulevard.
o Left-turn signal phasing
o Additional signing
o Signal head alignment adjustments with lanes
o Ladder-style crosswalk markings
• Filer Avenue and Locust Street Signalized Intersection. Lengthen pole for southbound
approach to realign signal heads above the appropriate lanes.
• Speed Feedback Signs at some locations (e.g., east of Twin Falls High School).
• Additional Intersection Lighting at the Eastland Drive N intersection.
The RSA team identified two other issues to review and consider:
High School Pedestrian Crossing. The pedestrian crossing at the Twin Falls High School is
heavily used before school, after school, and throughout the day as students cross to attend
seminary each period. The crossing should be upgraded from its current push-button LED flashers
to a pedestrian hybrid beacon crossing or something similar. The City could apply for an upcoming
Local Highway Technical Assistance Council (LHTAC) grant to upgrade the crossing. The pedestrian
and vehicle volumes, coupled with this being a school location, should result in a competitive grant
application.
Bicyclist and Pedestrian Accommodations. The Filer Avenue corridor has wide lanes which
could be repurposed to accommodate bike lanes and/or pedestrian improvements. The street is
classified as a collector, but nearby schools serve as motivators to keep vehicle speeds low. With
low speeds comes an opportunity to use Filer as a bicycle facility. Connectivity to existing or
planned bike facilities should be considered. The bike facility could be a cycle track, buffered bike
lanes, or painted bike lanes depending on space available and feasibility. If bike lanes are not
desired on Filer Avenue, there is still room to take some of the traveled way to expand sidewalks or
other pedestrian facilities (e.g., median refuge islands).
I® FILER AVENUE ROAD SAFETY AUDIT • ROAD SAFETY AUDIT REPORT • FEBRUARY 2022 37