Systemic Approach Source: St. Louis County, Minnesota

The Four Pillars 

of FoRRRwD

Roadway departures (aka lane departures) on 

the rural road network account for one-third of 

traffic fatalities. The FoRRRwD (Focus on Reducing 

Rural Roadway Departures) initiative encourages 

a systemic application of countermeasures that 

help keep vehicles in their travel lanes, reduce 

the potential for crashes, and decrease the 

severity of crashes that do occur.

FoRRRwD is supported by four pillars that work 

together to reduce rural roadway departures:

 Proven Countermeasures 

 Systemic Approach

 Safety Action Plans

 All Public Roads

Definition of Systemic

A “systemic safety improvement” means a 

proven safety countermeasure(s) that is widely 

implemented based on high risk roadway features 

that are correlated with particular severe crash 

types, rather than crash frequency.1

Severe crash locations are random. Severe crash 

types are not. A fundamental challenge on 

rural roads is that roadway departure (aka lane 

departure) crash locations are often scattered across 

the network and tend to change from year to year. 

In these situations, it is often not cost-effective to 

solely apply countermeasures where crashes already 

happened when they are unlikely to happen again 

at the same location in the near future.

The systemic approach uses crash data and 

roadway characteristic data to identify the types 

of crashes with the most potential for safety 

improvements (e.g. lane departure), as well as 

the roadway types where these severe crashes 

occur most often (e.g. two lane rural collectors). 

The agency can then identify risk factors—such as 

curve radii, traffic volumes, or shoulder widths—

that are typically associated with these crashes. 

These risk factors can be used to identify locations 

with higher risk for future severe crashes and apply 

proven countermeasures at these locations.

Benefits of a Systemic Approach:

 Targets locations of higher risk.

 Applies proven countermeasures at 

locations of higher risk.

 Prevents future severe crashes.

FHWA-SA-21-085 1

 23 USC 148(a)(12)

30 people will die today from rural 

roadway departure crashes. Let’s save 

the people behind the numbers.

https://safety.fhwa.dot.gov/FoRRRwD/
Noteworthy Practices

The following are examples of how local agencies have successfully implemented systemic safety 

improvements in their area. These agencies analyze data to identify risk factors, prioritize locations 

for projects, and institutionalize the systemic approach in policy and allocation of funding. The 

results have led to safer roads with fewer roadway departure fatalities and serious injuries.

Systemic Safety for All Public Roads

Minnesota

Minnesota has institutionalized the systemic 

approach at both the State and local level. Since 

2011, Minnesota has seen their 5-year averages 

decrease each year for lane departure fatalities. The 

Minnesota Highway Safety Improvement Program 

(HSIP) emphasized low-cost, high-benefit safety 

countermeasures that can be widely deployed on 

both State and local systems based on risk factors. 

The countermeasures that were deployed as a result 

of the systemic approach include horizontal curve 

signs, pavement marking and delineation, rumble 

strips, pavement widening with SafetyEdgeSM, and 

cable median barriers.

Nearly all rural roadways in the State are covered 

through District Safety Plans (State roads) and 

County Road Safety Plans (CRSPs) for each of 

the 87 counties (locally owned roads). Both these 

types of plans follow the same systemic analysis 

process, which includes analyzing crash data to 

identify risk factors and prioritizing projects with the 

largest number of risk factors. Then, analysts select 

countermeasures to address specific issues, which 

results in safety projects that can be submitted for 

funding. When administering the local HSIP, MnDOT 

prioritizes projects identified in CRSPs, which come 

from a documented systemic analysis. 

The following table shows the risk factors for curves and 

segments used in the 2016 District Safety Plans Update 

analysis for rural two-lane undivided county roads.

Table 1. Risk factors used in District Safety Plans. Source: 

recreated from MnDOT’s District Safety Plans Update.

Curves Segments

ADT ≥ 2,000 vehicles 

per day.

ADT ≥ 3,500 vehicles 

per day.

Shoulder width ≤ 4 feet. Shoulder width ≤ 2 feet.

Severe lane departure 

density ≥ 0.007 crashes 

per curve per year.

Severe lane departure 

density ≥ 0.014 crashes 

per mile per year.

Curve radius 500 to 

1,800 feet.

Critical radius curve 

density ≥ 0.1 curves 

per mile.

Presence of visual trap. Edge risk assessment of 

2 (medium) or 3 (high).

Presence of an 

Intersection on 

the curve.

Access density ≥ 8 

accesses per mile.

Addressing High Risk Rural Roads 

Kansas Department of Transportation

Between 2003 and 2008, over 65 percent of 

fatalities on Kansas roadways were the result of lane 

departures. During this same period, the greatest 

number of non-State road fatalities and serious 

injuries were on rural major collectors with a four-year 

average of 207. However, prior to 2011, High Risk Rural 

Roads (HRRR) projects were site-specific, manually 

plotted, and had no patterns identified due to the 

random nature of crashes; therefore, funds could 

not be used on sites without observed crash histories 

(even through risk factors were present). This resulted 

in Kansas not being able to justify enough projects to 

use the entire HRRR allotment (i.e., over 85 percent of 

funds were unobligated). 

In 2011, Kansas DOT adopted a systemic approach 

for HRRR funds to focus on rural major collectors. 

Kansas continued the HRRR program even after it was 

no longer a required set-aside of the HSIP. The HRRR 

funds are provided to local agencies that maintain 

roadways. Local agencies used funds to install lowcost countermeasures including striping, signing, 

high friction surface treatment, rumble strips and 

stripes, and clear zones improvements (extending 

culverts, tree removal). These countermeasures 

contributed to a decrease in fatalities and serious 

injuries on non-State rural major collectors to 189 

annually from 2012 to 2016.

In 2020, Kansas allocated $4.5M exclusively for 

locally-owned roads and all of this funding was 

obligated. To further the best use of HRRR funds, 

Kansas will require counties to have a Local Road 

Safety Plan (LRSP) to apply for HRRR funds. Each LRSP 

costs approximately 

$50,000, and with 

90-percent federal share

for HSIP, the county 

share is approximately 

$5,000. They are 

developing 20 plans 

per year and in 2021 will 

have completed plans 

for 60 counties. The 

LRSPs will be data-driven 

and focus on rural major

collectors and other 

paved county roads.

Figure 1. Chevrons at a horizontal 

curve in Kansas. Source: KDOT.
Figure 2. Breakdown of HSIP funding allocation. 

Source: recreated from TxDOT’s HSIP Guidelines.

Figure 3. High friction surface treatment at a curve in 

Foster, RI. Source: RIDOT. 

Institutionalizing the Systemic Approach

Texas Department of Transportation

The Texas Department of Transportation (TxDOT) 

revised its HSIP Guidelines to include systemic 

projects beginning in June 2020 for projects to be 

let in Fiscal Year (FY) 2022 and beyond. TxDOT will 

allocate 40 percent of their HSIP funds for systemic 

projects, with 25 percent for Districts (approximately 

$3M for each of the 25 Districts) and 15 percent for 

statewide systemic projects, such as median barrier. 

The TxDOT HSIP Guidelines have a list of 

four approved systemic roadway departure 

countermeasures that are proven to reduce 

fatalities and serious injuries - median barriers, 

roadway widening, corridor lighting, and enhanced 

delineation of curves. To prioritize locations with the 

most potential for safety improvement, TxDOT lists 

the following risk factors for the roadway departure 

systemic countermeasures:

• For median barrier, locations with medians of 70 feet 

or less are prioritized in the following order:

 1. Roadway type (interstate, non-interstate freeways, 

other principal arterials).

 2. Urban and rural median widths 0 to 45 feet.

 3. Median width greater than 45 feet in rural areas.

 4. Median width greater than 45 feet in urban areas.

• For roadway widening, the State prioritizes rural twolane undivided highways with paved surface width 

less than 24 feet. This also provides an opportunity to 

add rumble strips to further improve safety.

• For enhanced delineation of curves, agencies will 

treat curves within a geographical area or roadway 

type, not single locations. 

• For corridor lighting, agencies will implement 

continuous safety lighting along roadway corridors 

where no lighting exists, not single locations. 

TxDOT has approved 174 systemic HSIP projects in 

the FY 2022-2024 call for projects; 97 projects (56 

percent) are lane departure projects. These lane 

departure projects include 14 projects installing 

chevrons and LED chevrons 

at curves, 31 projects adding 

or widening shoulders, and 52 

median barrier projects.

The systemic approach is also 

being institutionalized into the 

District Safety Plans beginning 

in FY 2020. The District Safety 

Plans act as a project planning 

document across all funding 

categories, including the HSIP, 

and will be updated annually. 

Prioritizing Systemic Projects for 

Horizontal Curves Rhode Island Department of Transportation

The Rhode Island Department of Transportation 

(RIDOT) performed a systemic analysis that 

identified focus crash and facility types for 

horizontal curves to identify risk factors for prioritizing 

locations for safety improvement. With Rhode Island 

being a small State, using fatal and serious injury 

crashes provided a small sample size; therefore, 

the analysis used all injury crashes. The risk factors 

identified for the systemic analysis were curve 

radius, shoulder width, Average Annual Daily Traffic 

(AADT), and functional classification. The existing 

RIDOT Model Inventory of Roadway Elements (MIRE) 

data was used to identify the presence of the risk 

factors and obtain a risk “score” for each curve 

location. This score assisted RIDOT in prioritizing the 

curve locations for countermeasure implementation 

into their Transportation Improvement Plan and HSIP. 

As an example, for fixed-object crashes at 

horizontal curves with radii less than 400 feet, RIDOT 

used the following risk factor scoring:

• No shoulder present: 2 

• Right shoulder width between 1 feet and 4 feet: 1 

• AADT less than 2,500 vehicles per day: 2 

• AADT between 2,500 and 7,500 vehicles per day: 1 

• Predicted KA curve crashes as a function of 

radius (in feet): 31.377 × Radius − 0.391

RIDOT developed a flow chart which streamlined 

the diagnosis process. The designer begins with 

planning-level MIRE data and collects additional 

data in the field, such as stopping sight distance, 

speeds, and presence of signage for each project. 

RIDOT uses the information collected in the field, 

along with a detailed crash review (if crashes 

occurred) and applies it to the flow chart to select 

the appropriate countermeasure (or enhancements 

to existing countermeasures). Once a 

countermeasure 

is identified, the 

improvements are 

programmed to 

be implemented 

via maintenance 

work order 

(signing, striping, 

guardrail) or as 

part of a contract 

(High Friction 

Surface Treatment, 

shoulder 

widening). 
Horizontal Curve Safety for Two-Lane 

Rural Roads

Maine Department of Transportation

Lane departure crashes are a major concern 

for Maine, with 72 percent of fatal crashes being 

classified as went-off-road (49 percent) and headon (23 percent). Two thirds of the fatal and serious 

injury crashes occur on rural two-lane roads. To 

address the lane departure crashes, Maine DOT 

used the systemic approach to prioritize locations 

for treatment based on risk factors. 

The risk factor categories evaluated included 

horizontal curvature, vertical curvature, grade, 

posted speed limit, light condition, road surface 

condition, and AADT. For each of the risk factor 

categories, Maine DOT used a “relative risk ratio” 

to determine relative risk by comparing the 

percentage of fatal and serious injury crashes to the 

exposure, measured in vehicle miles traveled (VMT). 

The analysis found that horizontal curvature 

represented the greatest risk factor for rural twolane highways. A more detailed review of fatal and 

serious injury crashes found that 84 percent of the 

crashes are directed toward the outside of the 

curve and 39 percent involve vehicles crossing the 

centerline. Maine DOT plans to install center line 

rumble strips and edge line rumble strips on the 

outside (high-side) of the curve to target a greater 

proportion of crashes. To identify curves where 

rumble strip could be implemented cost-effectively, 

Maine DOT estimated the benefit/cost (B/C) ratios 

of rumble strip installations on hypothetical curves 

of varying AADT and horizontal curvature using 

crash modification factors and the risk factor 

analysis. The results showed that very high B/C 

ratios can be achieved on rural two-lane highways 

where AADTs are relatively high (10,000 to 15,000) 

and radii is relatively small (less than 1,400 ft). 

Maine DOT will install rumble strips in coordination 

with the resurfacing and paving schedule for twolane rural highways to minimize costs.

Improving Safety in Tribal Areas

Sisseton-Wahpeton Oyate Tribe

In the Lake Traverse Reservation, 70 percent of 

fatalities and 60 percent of injury crashes are 

attributed to vehicles leaving the roadway. To 

address this trend, the Sisseton-Wahpeton Oyate 

(SWO) Tribe participated in a safety improvement 

program through the Wyoming Technology 

Transfer Center/Local Technical Assistance 

Program and the Northern Plains Tribal 

Technical Assistance Program.

A systemic safety study was conducted for the 

SWO Tribe, which included crash data analysis 

and a field safety evaluation. The field evaluation 

provided scoring for 5 categories—general 

roadway conditions, intersections, signage and 

pavement markings, fixed objects, and shoulder/

right-of-way. The field evaluations scores were 

ranked and combined with the crash data 

ranking to provide a list of proposed roadways 

to be considered for safety improvements. The 

combination of historical crash data and field 

evaluations provided a substantive basis for 

identifying high risk locations. 

Cost estimates and a benefit-cost analysis gave 

the SWO Tribe a method to prioritize the projects. 

The analysis showed that for straight roadways 

with little or no shoulder, the majority of crashes 

were run-off-road (rollovers or hit fixed object). To 

combat this issue, the plan recommended (1) 

longitudinal shoulder rumble strips where shoulders 

exist and (2) a rumble strip applied at the edge 

line on roadways without shoulders. As a result of 

these findings, the Tribe received a grant from the 

Federal Highway Administration Office of Tribal 

Transportation’s Tribal Transportation Program 

Safety Fund to implement edge line rumble 

stripes on almost 31 miles of roadways with these 

higher-risk characteristics.

Figure 4. Center line and edge line rumble strips on a 

horizontal curve in Maine. Source: Maine DOT.

Figure 5. Injury Crash Types, 2009-2018. Source: recreated 

from SWO Tribal Transportation Safety Plan.

Resources

FHWA Systemic Safety Web Page https://safety.fhwa.dot.gov/systemic/

FHWA has developed a 4-hour training course on the systemic approach that can be requested 

through your LTAP Center https://nltapa.org/regions/, State DOT https://www.fhwa.dot.gov/about/

webstate.cfm, or FHWA Division Office https://www.fhwa.dot.gov/about/field.cfm.