FHWA-SA-24-005

Federal Highway Administration

Proven Safety Countermeasures in

Rural Communities
SPEED MANAGEMENT

Speed Safety 

Cameras Variable Speed Limits Appropriate Speed Limits for All Road Users

ROADWAY DEPARTURE

Wider Edge Lines Enhanced Delineation 

for Horizontal Curves

Longitudinal Rumble 

Strips and Stripes on 

Two-Lane Roads

SafetyEdgeSM

Roadside Design 

Improvements at 

Curves

Median Barriers

INTERSECTIONS

Backplates with 

Retroreflective 

Borders

Corridor Access 

Management

Dedicated Left- and 

Right-Turn Lanes at 

Intersections

Reduced Left-Turn 

Conflict Intersections Roundabouts

Systemic Application 

of Multiple Low-Cost 

Countermeasures at 

Stop-Controlled 

Intersections

Yellow Change 

Intervals

PEDESTRIANS/BICYCLES

Crosswalk Visibility 

Enhancements Bicycle Lanes

Rectangular Rapid 

Flashing Beacons 

(RRFB)

Leading Pedestrian 

Interval

Medians and Pedestrian 

Refuge Islands in Urban 

and Suburban Areas

Pedestrian Hybrid 

Beacons

Road Diets (Roadway 

Reconfiguration) Walkways

Crosscutting

Pavement Friction 

Management Lighting Local Road Safety Plans

Road Safety Audit

From 2017 to 2021, over 83,000 people died on rural 

roadways; this accounts for 43 percent of all roadway 

deaths despite only 20 percent of the U.S. population 

residing in these areas and only 31 percent of vehicle 

miles traveled occurring in rural areas.1,2 Furthermore, 43 

percent of speed- related fatalities, 56 percent of roadway 

departure fatalities (i.e., a crash that occurs after a vehicle 

crosses an edge line or center line or otherwise leaves the 

traveled way), and 26 percent of all intersection fatalities 

occurred in rural areas. Across the same time period, 

over 6,400 pedestrians and bicyclists were killed on rural 

roadways.3

The Federal Highway Administration (FHWA) has identified 

28 Proven Safety Countermeasures (PSCs) to reduce fatal 

and serious injury crashes on roads nationwide (see figure 

1). These PSCs are applicable for a range of contexts, road 

types, and governing agencies across the country. The 

PSCs can offer significant and measurable impacts across 

an agency’s rural road network as part of their approach to 

improving safety.

The PSCs can support agencies with implementation of the 

Safe System Approach, which seeks to build and reinforce 

multiple layers of protection to both prevent crashes from 

happening and minimize the harm caused to those involved 

when crashes do occur. Implementing a Safe System 

Approach requires collaborative engagement among a 

diverse group of stakeholders to increase safety for all 

road users. Accordingly, agencies should consider how the 

PSCs and National Highway Traffic Safety Administration’s 

(NHTSA) Countermeasures that Work4

 can create a system 

with redundancies in place to protect all road users.

Introduction OFFICE OF SAFETY

Proven Safety Countermeasures

1 https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813336

2 https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813488

3 2017-2021 FARS query

4 https://www.nhtsa.gov/book/countermeasures/countermeasures-work

Figure 1. FHWA’s 28 Proven Safety Countermeasures. Source: FHWA. 2
Guide Contents

The following pages highlight a subset of the PSCs with direct application in rural areas. The highlights describe the PSC, include considerations, crash reduction 

effectiveness, and case studies and resources. This guide is organized by these focus areas and includes a crosscutting section for PSCs that apply to more than 

one area. 

Within this guide, crash reduction effectiveness is presented for each PSC. This effectiveness data draws from the Crash Modification Factors (CMF) Clearinghouse,5

 which 

provides a searchable database of CMFs along with guidance and resources on using CMFs in road safety practice. The CMF Clearinghouse ID number is listed for each 

effectiveness citation. Where available, the guide provides data on crash reductions on rural roads. However, in several cases there was not research or studies available 

regarding the effectiveness on rural roads. This does not suggest that the PSCs are not effective on rural roads, but rather more studies are 

necessary to better quantify their effectiveness.

Through implementation of the PSCs, agencies can reduce rural road fatalities and serious injuries for all users. Agencies should consult the PSC webpage6

 for additional 

information on each PSC, including a search and filter function.

7

 Users answer questions regarding area type, functional classification, traffic volumes, safety problem(s) to 

be addressed, targeted crash types, and other information to receive a list of PSCs meeting the criteria. The search function allows users to obtain a tailored list of potential 

PSCs and assists practitioners with identifying the most appropriate PSC(s) for their location of interest. 

This guide also features a Desktop Reference table of PSCs that may be considered in rural communities and compares Safe System design hierarchy alignment, relative 

cost, unpaved road applicability, relative crash reduction, and typical service life.

5 https://www.cmfclearinghouse.org/

6 https://highways.dot.gov/safety/proven-safety-countermeasures 

7 https://highways.dot.gov/safety/proven-safety-countermeasures/search 3

Reference Areas

1 Focus Area

2 Rural Applications/Considerations

3 Crash Reduction Effectiveness

4 Case Studies

5 QR Code to PSC Webpage

3

Figure 2. Example image of a PSC page within this guide.

Rural agencies and communities should consider implementing PSCs that 

address at least one of four focus areas:

• Roadway Departure

• Intersections

• Pedestrian/Bicyclist

• Speed Management
Photo Placeholder

Roadway Departure

Wider Edge Lines

Rural Applications/Considerations Wider edge lines (6 inches, per MUTCD Section 3A) improve visibility 

of travel lane boundaries compared to traditional edge lines (4 inches) and can provide safety benefits to all 

facility types (e.g., freeways, multilane divided and undivided highways, two-lane highways). Wider edge lines 

are commonly installed on rural two-lane highways, particularly those with a history of single-vehicle roadway 

departure crashes. Wider edge lines are a low-cost countermeasure. Installing wider edge lines over rumble strips 

(i.e., rumble stripes) can improve marking longevity and visibility in areas with snowplow operations.

Effectiveness of Widening Edge Lines (from 4 to 6 inches)

• 37% reduction in fatal and injury crashes on rural two-lane roads (CMF ID 4737).

Case Studies

▷ Missouri undertook a major road surface improvement program in 2005-06 and analyzed three years of both 

pre- and post-installation crash data. The analysis revealed a 22% reduction in fatal and injury crashes on rural 

freeways from installing wider edge line markings as a standalone treatment. https://spexternal.modot.mo.gov/

sites/cm/CORDT/cmr12-002.pdf

▷ Idaho evaluated the safety effects of using wider edge line markings on their rural two-lane highway system. 

Results indicated a benefit-to-cost ratio of 25:1. https://rosap.ntl.bts.gov/view/dot/63580#:~:text=The%20

reduction%20in%20crash%20rates,the%2095%20percent%20confidence%20level

Rumble Strips and Stripes

Rural Applications/Considerations Center line and shoulder rumble strips and stripes (where the pavement 

marking is placed over the rumble strip) are milled or rolled-in corrugations in the pavement to alert inattentive 

drivers that they are leaving their lane. Center line rumble strips/stripes can be used in both passing and no 

passing zones wherever an agency has identified risk factors (such as lane width, shoulder width, median type, 

horizontal curvature, or crash history), that indicate a higher probability of head-on crashes. Consider shoulder or 

edge line rumble strips/stripes wherever risk factors indicate a higher probability of run-off-road crashes.

Effectiveness

• Center line rumble strips on two-lane roads have resulted in a 44% to 64% reduction in head-on and opposite 

direction sideswipe fatal and injury crashes (CMF IDs 3358, 3356). 

• Shoulder rumble strips on rural freeways have resulted in a 13% to 51% reduction in run-off-road fatal and injury 

crashes (CMF IDs 3425, 3648).

Case Study and Resources 

▷ To reduce roadway departure crashes on rural roads, Mercer County, NJ implemented 6 miles of center 

line rumble stripes across 18 different roads after seeing favorable results from pilot projects. Community 

backlash subsided after public outreach regarding safety benefits. https://safety.fhwa.dot.gov/FoRRRwD/

Countermeasure4-pager.pdf

▷ FHWA developed the Sweet Sound of Safety informational video to highlight the safety benefits of centerline and 

shoulder rumble strips for community outreach purposes. https://youtu.be/2V5-M4-O70E

4

Figure 4. Shoulder rumble strips. Source: FHWA

Figure 3. Wider edge lines enhance visibility of the 

travel lane. Source: Thurston County, WA
Roadway Departure

Enhanced Delineation for Horizontal Curves

Rural Applications/Considerations Horizontal curves are common crash locations, particularly at night or 

during inclement weather. Improving curve delineation through signage and/or pavement markings can promote 

proper vehicle alignment through the curve. There are a wide range of options available for improving horizontal 

curve delineation in advance of or within curves, either in combination or individually; common treatments 

include pavement markings, in-lane curve warning pavement markings, retroreflective strips on signposts, 

delineators (post-mounted or guardrail-mounted), chevrons, improving sign conspicuity (larger, fluorescent, and/or 

retroreflective signs), and dynamic warning signs or chevrons.

Effectiveness

• Installing chevrons on horizontal curves on rural two-lane roads has resulted in a 16% reduction in fatal and 

injury crashes overall and a 25% reduction in nighttime crashes. (CMF IDs 2438, 2439).

• Installing in-lane curve warning pavement markings on rural two-lane roads has resulted in 35% reduction in 

total crashes. (CMF ID 10312).

Case Study and Resources 

▷ Bonner County, ID improved visibility at higher-risk rural horizontal curves by installing edge lines and 

delineators. The public has responded positively and requested the countermeasures at more locations. https://

safety.fhwa.dot.gov/FoRRRwD/Countermeasure4-pager.pdf

▷ FHWA developed an instructional video for proper chevron sign spacing on horizontal curves. https://www.

youtube.com/watch?v=LeI9_rffS34

Roadside Design Improvements at Curves

Rural Applications/Considerations Horizontal curves are associated with about 27 percent of all fatal 

crashes, and around 80 percent of those are roadway departure crashes. Improving the roadside environment 

can give vehicles space to recover safely and reduce the severity of crashes that occur. Typical roadside design 

improvements include vegetation management, delineation/relocation/removal of roadside objects, clear zone 

widening, flattening of side slopes, adding or widening shoulders, and installing roadside barrier.

Effectiveness

Widening the clear zone through tree removal on rural two-lane highways:

Increase distance to treeline by 

• 5 to 8 ft: 35-49% reduction in total crashes.

• 10 to 13 ft: 57-66% reduction in total crashes.

(Source: NCHRP Report 440 https://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_440.pdf) 

Case Study and Resources

▷ Lapeer County, MI, developed a proactive tree removal and trimming program by targeting locations for 

treatment using identified risk factors to reduce fixed object crashes on rural roads. 

https://safety.fhwa.dot.gov/FoRRRwD/Countermeasure4-pager.pdf

▷ Refer to the Rural Roadway Departure Countermeasure Pocket Guide for more information on this PSC. 

https://safety.fhwa.dot.gov/FoRRRwD/RwDPocketGuide.pdf

5

Figure 6. Inside shoulder widening at a horizontal 

curve. Source: FHWA

Figure 5. Curve delineation enhancements may 

include in-lane curve warning pavement markings 

and chevron signs with retroreflective strips on 

sign posts. Source: FHWA
Photo Placeholder

Intersections

Roundabouts

Rural Applications/Considerations Roughly one-third of intersection fatalities occur on rural two-lane highways, 

with posted speed limits over 40 mph. Unlike traditional intersections, roundabouts require yield control on entry 

and splitter islands on the approaches to reduce speeds both on approach and within the intersection. Single lane 

roundabouts at 4-legged intersections have 8 conflict points compared to 32 conflict points for a stop-controlled 

intersection. Roundabouts can reduce severe crashes (i.e., angle crashes) at intersections and travel delays at both 

isolated intersections and within rural town centers.

Effectiveness of Converting High-Speed Rural Intersection (4-leg) to Roundabout

• 68% reduction in total crashes (CMF ID 4697).

• 88% reduction in injury crashes (CMF ID 4698).

Case Studies

▷ Kansas DOT collaborated with freight stakeholders to design a roundabout that would reduce speeds and crashes 

without sacrificing mobility for truck drivers. In the 6 years following installation, there were zero injury crashes 

recorded at the intersection. https://highways.dot.gov/sites/fhwa.dot.gov/files/2022-06/fhwasa14013_0.pdf

▷ A successful community outreach program on roundabouts educating skeptical residents in Brown County, WI 

resulted in the implementation of two successive roundabouts within a busy school zone and the reverse of a 

policy prohibiting students from biking and walking to school. 

https://highways.dot.gov/sites/fhwa.dot.gov/files/2022-06/fhwasa11031.pdf

Systemic Application of Multiple Low-Cost Countermeasures at 

Stop-Controlled Intersections

Rural Applications/Considerations Systemically deploying multiple low-cost treatments to many stopcontrolled intersections throughout a jurisdiction can maximize resources and reduce crashes. Examples of 

common treatments include enhanced pavement markings, retroreflective signpost sheeting, advance warning 

signs, doubled-up signs, flashing beacons, oversized signs, and sight distance improvements.

Effectiveness

• 15% reduction in nighttime crashes at all intersection locations/types/areas (CMF ID 8870).

• 27% reduction in fatal and injury crashes at rural intersections (CMF ID 8874).

Case Studies

▷ Louisiana DOT installed low-cost safety treatments at 89 stop-controlled intersections and found a 56% reduction 

at three-legged intersections and 64% reduction at four-legged intersections of fatal and injury crashes. 

https://highways.dot.gov/sites/fhwa.dot.gov/files/2022-06/fhwasa18047.pdf

▷ South Carolina DOT implements a variety of low-cost countermeasures at stop-controlled intersections 

throughout the State as part of their proactive approach to intersection safety. According to a follow-up study, 

this approach led to a 27% reduction in fatal/injury crashes and a 25% reduction in total crashes at rural 

intersections. https://highways.dot.gov/sites/fhwa.dot.gov/files/2022-06/fhwasa12021.pdf

6

Figure 8. Doubled up “Stop Ahead” warning signs 

with retro-reflective strips on sign posts. Source: 

PennDOT

Figure 7. Single lane roundabout in a rural area.

Source: Caltrans

Basic plan showing low-cost countermeasures at a 

stop-controlled T-intersection. Source: FHWA
Pedestrian/Bicyclist 

Road Diets/Reconfiguration 

Rural Applications/Considerations A road diet is a conversion of an existing road to reduce the number of through 

lanes and reallocate roadway space to other uses (e.g., bicycle lanes, sidewalks, and parking). Often this will consist 

of reducing four-lane roads to three lanes, with the middle lane serving as a two-way left-turn lane or combination of 

median and left-turn lanes; this can reduce travel speeds, ease pedestrian crossing difficulties, and reduce crashes. 

In rural areas without sidewalks, increasing the paved shoulder width by removing a travel lane can accommodate 

non-motorized users. A road diet can be a low-cost safety solution when planned in conjunction with a simple pavement 

overlay. 

Effectiveness 

• Convert 4-lane undivided road to 2-lanes plus turning lane: 37% reduction in injury crashes (CMF ID 11231).

Case Studies

▷ Battle Lake, MN revitalized their downtown streets with a successful road diet implementation alongside pedestrian 

and bicycle improvements. MnDOT noted that crashes have been reduced in the four years following the road diet. 

https://www.dot.state.mn.us/trafficeng/safety/road-diet-battle-lake.html

▷ Residents of Colorado have been advocating for bicycle infrastructure since the 1940s to connect western townships 

and improve non-vehicular mobility throughout the region. The Eagle Valley Trail, set to be completed in 2024, 

consists of over 60 miles of paved pathways throughout the region. https://www.eaglevalleytrail.org/

Crosswalk Visibility Enhancements 

Rural Applications/Considerations High-visibility crosswalk markings, lighting, and supplemental signing and 

pavement markings can improve driver awareness of crosswalks and non-motorized road users (e.g., pedestrians, 

bicyclists, wheelchair and other mobility device users, public transit users) at rural locations. These devices also help 

channelize crossing movements to locations where drivers expect them to occur. Crosswalk visibility enhancements 

can be installed as standalone devices if desired, but multiple treatments are encouraged to maximize safety benefits.

Effectiveness

• Install intersection lighting: 42% reduction in nighttime vehicle-pedestrian injury crashes and 78% reduction in 

fatal vehicle-pedestrian crashes (CMF IDs 436, 435). 

• Install rural highway lighting: 28% reduction in nighttime injury crashes (CMF ID 192).

• Install high-visibility crosswalks at urban intersections (i.e., town centers): 40% reduction in pedestrian injury 

crashes (CMF ID 4123).

Case Study and Resources 

▷ In Kansas, the Flint Hills Metropolitan Planning Organization has modified crosswalks with a multitude of 

quick-build (i.e., common projects include curb extensions and pedestrian islands) techniques and public 

demonstrations. Common projects include curb extensions and pedestrian islands. https://www.flinthillsmpo.

org/demoprojects

▷ The Pedestrian Lighting Primer provides information on lighting design considerations for locations with 

pedestrian activity. https://highways.dot.gov/sites/fhwa.dot.gov/files/2022-09/Pedestrian_Lighting_Primer_

Final.pdf

▷ FHWA is promoting traffic control devices and properly designed lighting to improve safety for all users as 

part of the Every Day Counts Nighttime Visibility for Safety initiative. https://www.fhwa.dot.gov/innovation/

everydaycounts/edc_7/nighttime_visibility.cfm 7

Figure 10. Crosswalk visibility enhancements 

include advance yield markings, high visibility 

crosswalk markings, lighting, and a rectangular 

rapid flashing beacon. Source: FHWA

Figure 9. Example of a roadway reconfiguration 

using available roadway width to include bicycle 

lanes. Source: Rural Design Guide
Figure 11. Flashing beacons alerting drivers to decrease speeds in a school zone. Source: FHWA

8

Speed Management

Figure 12. HFST applied at a horizontal curve.

Source: Maricopa County, AZ Pavement Friction 

Rural Applications/Considerations Pavement friction is a critical component of roadway performance, 

particularly in rural areas with higher speeds and sharp curves or intersections. Measuring, monitoring, and 

maintaining pavement friction at locations where vehicles frequently turn, slow, or stop can improve performance 

and reduce roadway departure, intersection-related, wet-road, and pedestrian crashes. Where increased friction 

is desired, agencies can install a High Friction Surface Treatment (HFST) on the pavement to enhance friction and 

skid resistance. HFSTs are applied directly on stable, existing pavement and costs can be reduced by bundling 

installations at multiple locations.

Effectiveness of Installing HFSTs on two-lane rural roads 

• 48% reduction in injury crashes (CMF ID 10333).

• 72% reduction in run-off-road crashes (CMF ID 10334). 

Case Study 

▷ Maricopa County, AZ applied HFST to multiple horizontal curves identified based on crash history. Before HFST 

installation, one location had 35 crashes (7 of which resulted in severe injuries) over a 5-year period. Only 

1 crash occurred on the curve in the 13 months following installation. https://safety.fhwa.dot.gov/forrrwd/

hfst4localsstoryboard/page09.html

Crosscutting

Appropriate Speed Limits for All Road Users

Rural Applications/Considerations Setting speed limits that are consistent and reasonable for local conditions 

is critical for effectively managing travel speeds and reducing crash severity. When setting speed limits, agencies 

should consider non-vehicular activities, types of road users present, crash history, land use context, traffic 

volumes, and observed speeds, among other factors. An effective speed management program uses multiple 

strategies concurrently with setting speed limits, such as traffic calming features, design features, high-visibility 

enforcement, and speed safety cameras, that encourage compliance with the posted speed limit.

Effectiveness

• Research shows setting a lower speed limit, in conjunction with other speed management strategies, on rural 

roads can reduce fatal and injury crashes up to 40% and lead to drivers complying more closely with the 

posted speed limit (CMF ID 10249).

• Installing a speed feedback sign in advance of horizontal curves on high-speed rural roads can reduce all 

crashes by 7% (CMF ID 6886).

Case Studies

▷ Iowa DOT used a variety of speed management techniques to address transitions zones from 55 mph to 25 mph 

in rural communities, resulting in a 53% to 100% decline in excessive speeding (i.e., >15 mph over speed limit) 

and 2.3 to 7.6 mph decline in average speeds across the range of treatments. https://safety.fhwa.dot.gov/

speedmgt/ref_mats/fhwasa16079/

▷ Jefferson County, MO evaluated speed limits at 19 school zone locations on County-maintained roads and found 

that 11 locations had 85th percentile speeds higher than posted speed limits when school was in session. 

https://www.jeffcomo.org/DocumentCenter/View/12886/JCPW-Traffic-Safety-Improvement-ProgramSummary-PDF
Crosscutting

Road Safety Audit (RSA)

Rural Applications/Considerations An RSA is a formal evaluation of the safety performance of an existing or 

future road segment or intersection that is performed by an independent, multidisciplinary team. RSAs can be 

performed at any point in the project development process, including during planning and construction periods, 

and on any sized existing roadways. RSAs conclude with a formal report that accounts for human factors, the 

built environment, and all modes of transportation. RSAs are an objective review of project locations and can 

result in a wide variety of safety-related recommendations, including other PSCs, that are more comprehensive 

than a traditional safety review performed by a project design team. RSAs are a great way to engage community 

representatives that have a vested interest in project outcomes.

Effectiveness 

• Performing an RSA and implementing recommendations: 10% to 60% reduction in total crashes. 

(Source: https://safety.fhwa.dot.gov/rsa/case_studies/fhwasa12037/ and https://safety.fhwa.dot.gov/rsa/

guidelines/documents/FHWA_SA_06_06.pdf).

Case Study and Resources

▷ Twelve RSAs were completed in South Dakota for a variety of facility types, including county roads, gravel roads, 

intersections, and railroad crossings. https://rosap.ntl.bts.gov/view/dot/64141

▷ The Road Safety Audit Toolkit for Federal Land Management Agencies and Tribal Governments provides the 

framework for developing and implementing a successful RSA program. https://safety.fhwa.dot.gov/rsa/

resources/toolkitflh/toolkitflh.pdf

Local Road Safety Plan (LRSP)

Rural Applications/Considerations An LRSP provides a framework for identifying, analyzing, and prioritizing 

roadway safety improvements on all local and Tribal roads within a jurisdiction. The successful development of an 

LRSP engages multiple stakeholders, uses a data-driven approach, and results in a list of issues, risks, actions, 

and improvements that are tailored and prioritized based on local needs to aid agencies in reducing fatalities and 

serious injuries on their road network.

Effectiveness of Implementing LRSPs

• 25% reduction in county road fatalities in Minnesota.

• 17% reduction in fatal and serious injury crashes on county-owned roads in Washington.

• 35% reduction in severe curve crashes in Thurston County, WA.

Case Studies and Resources 

▷ LRSPs in California: https://youtu.be/PJ0Iid8izvI

▷ Local agency insights: https://youtu.be/V_apdVeEbQ4

▷ Short informational video on LRSPs: https://youtu.be/Wzdm798MoI8

▷ Visit the LRSP Do-It-Yourself website developed by FHWA for more information and guidance for 

developing an LRSP: https://highways.dot.gov/safety/local-rural/local-road-safety-plans

9

Figure 14. Example of roadway improvements that 

may be included in an LRSP. Source: FHWA

Figure 13. RSA participants conducting a site visit.

Source: FHWA
Desktop Reference

The Rural PSC Desktop Reference only includes PSCs most applicable to a local and rural road context. For more information on the complete list of PSCs, refer to FHWA’s 

PSC webpage.8 The Desktop Reference includes information in four key categories: how the countermeasure addresses the Safe System design hierarchy, representative 

cost ranges for installation, common crash reduction ranges, and typical service life for the countermeasure.

1 – Safe System Roadway Design Hierarchy Alignment

• Remove Severe Conflicts - Eliminating specific high-risk conditions, such as 

separating road users moving at different speeds or different directions in 

space to minimize conflicts.

• Reduce Vehicle Speeds - Implementing design features and speed management 

strategies to reduce vehicle speeds; effectively reduces the kinetic energy 

involved in a crash should it occur.

• Manage Conflicts in Time - Separating the users in time using traffic control 

devices, such as traffic signals or hybrid beacons, to minimize vehicle conflicts 

with vulnerable road users.

• Increase Attentiveness and Awareness - Alerting roadway users to certain types 

of conflicts so that appropriate action can be taken. 

• Find more information on the Safe System Approach at https://highways.dot.

gov/safety/zero-deaths.

2 – Cost Ranges

• Low-cost (L) – up to $5,000 per mile or per curve/location.

• Medium-cost (M) – $5,000 to $50,000 per mile or per curve/location

• High-cost (H) – More than $50,000 per mile or per curve/location. 

• Note that costs can vary considerably due to local conditions.

3 – Crash Reduction9

• Low (L) = greater than 0% and less than 25% reduction.

• Medium (M) = greater than 25% and less than 50% reduction.

• High (H) = greater than 50% reduction.

4 – Typical Service Life

• The Highway Safety Manual (HSM) defines countermeasure service life as “the 

number of years in which the countermeasure is expected to have a noticeable 

and quantifiable effect on the crash occurrence at the site.” 

• See the FHWA Countermeasure Service Life Guide for more information on 

Countermeasures Service Life at https://safety.fhwa.dot.gov/hsip/docs/FHWASA-21-021_Countermeasure_Serv_Life_Guide.pdf.

10

1 2 3 4

Figure 15. Excerpt of the Rural PSC Desktop Reference table columns.

8 https://highways.dot.gov/safety/proven-safety-countermeasures

9 All cited crash reductions are consistent with the PSC fact sheets and materials. For purposes of this resource, there was a focus on crash reductions on rural roads. However, in several cases there was 

not research or studies available regarding the effectiveness on rural roads. This does not suggest that the PSCs are not effective on rural roads, but rather more implementation or evaluation is necessary 

to better quantify their effectiveness.
Focus Area Proven Safety Countermeasure

Safe System Design Hierarchy Alignment

Cost

L-M-H

Option on 

Unpaved 

Roads

Crash 

Reduction

L-M-H

Typical 

Service Life 

(in years)

Remove 

Severe 

Conflicts

Reduce 

Vehicle 

Speeds

Manage 

Conflicts 

in Time

Increase 

Attentiveness 

and Awareness

Speed 

Management

Appropriate Speed Limits for All Road Users - Yes - - L Yes L-M 15

Speed Safety Cameras - Yes - - M-H - M-H 10

Variable Speed Limits - Yes - Yes L-H - M-H 10

Pedestrian / 

Bicyclist

Bicycle Lanes Yes - - - L-M - M 20

Crosswalk Visibility Enhancements - - - Yes L-M - M 5

Medians and Pedestrian Refuge Islands Yes Yes - - M - M-H 20

Road Diets (Roadway Reconfiguration) Yes Yes - - L-H - M 20

Walkways Yes - - - L-H Yes H 20

Rectangular Rapid Flashing Beacon (RRFB) - - - Yes L - M 10

Roadway 

Departure

Enhanced Delineation for Horizontal Curves - - - Yes L Yes L-H 10-15

Longitudinal Rumble Strips and Stripes - - - Yes L - M-H 10

Median Barriers Yes - - - M-H - H 25

Roadside Design Improvements at Curves Yes - - - L-H Yes L-M 10-20

SafetyEdgeSM Yes - - - L - L 10

Wider Edge Lines - - - Yes L - M 5

Intersection

Roundabouts Yes Yes - - M-H - H 20

Systemic Application of Multiple Low-Cost 

Countermeasures at Stop-Controlled Intersections - - - Yes L Yes L 15

Dedicated Left and Right Turn Lanes 

at Intersections Yes - - - M - M 20

Corridor Access Management Yes - - - L-M - M 20

Crosscutting

Lighting - - - Yes M-H Yes M 15

Local Road Safety Plans Yes Yes Yes Yes L-H Yes M -

Pavement Friction Management Yes Yes - - M - M-H 10

Road Safety Audits Yes Yes Yes Yes L-H Yes L-H -

11

Table 1. The Rural PSC Desktop Reference 

Reference
Office of Safety

Proven Safety Countermeasures