Roadway Departure

Almost 60 percent of all U.S. roadway fatalities occur as a result 

of roadway departure crashes.1

 

Advanced Crash Analysis Program

Advanced finite element models and crash simulations are used to 

(1) study the effectiveness of roadside hardware such as guardrails, 

sign supports, and concrete barriers; (2) assess how differences 

in vehicle characteristics affect vehicle-to-hardware impacts; (3) 

investigate crash causes; (4) formulate improved guidelines for the 

selection and deployment of roadside hardware; and (5) develop 

concepts for new roadside treatments. These efforts provide 

transportation agencies with new ways to mitigate roadside safety 

problems. Researchers are developing guidelines for the design 

and placement of cable median barriers, analyzing roadside terrain 

effects on vehicle trajectories, and evaluating how commonly used 

roadside hardware will perform under proposed new national 

crashworthiness criteria. The models, data, and results of this 

program are freely shared and have been the basis for other safety 

research worldwide.

Managing Pavement Marking Retroreflectivity

FHWA is developing minimum standards for pavement marking 

retroreflectivity for inclusion in the Manual on Uniform Traffic Control Devices. Research supporting this effort focuses on 

identifying how to utilize these minimum standards in pavement 

marking management procedures so that States and municipalities 

can maintain pavement markings at a level that provides drivers 

with the information they need to make safe driving decisions.

Pavement Marking Demonstration Projects

During demonstration projects in Alaska and Tennessee, researchers will consider the cost effectiveness of different pavement 

marking systems, the safety effects of increasing pavement edgeline 

widths, the potential environmental impacts of the pavement 

marking systems included in the study, and the effects of state 

bidding and procurement processes on the quality of pavement 

marking materials used.

Intersections

Intersection-related crashes make up 21 percent of all fatal 

crashes.1

 

Intersection/Interchange Improvements

Researchers are developing and evaluating novel intersection 

designs to improve intersection safety while also increasing 

capacity, reducing congestion, and minimizing infrastructure costs. 

These designs include the Diverging Diamond Interchange (DDI), 

the New Jersey Jughandle Intersection, median U-turn intersection 

treatments, and the Continuous Flow Intersection (CFI). While 

some of these intersection designs are under construction, 

researchers are using the Highway Driving Simulator in the FHWA 

Human Centered Systems Laboratory to collect drivers’ evaluations 

of interchange geometries and marking and signage alternatives. 

Also under development is the Cooperative Intersection Collision 

Avoidance System (CICAS), which warns drivers about to violate 

a red light and helps drivers correctly judge gaps in traffic when 

making left turns. Under field evaluation is the Detection-Control 

System (D-CS), which detects vehicles approaching isolated rural 

intersections at high speeds and alters traffic signal timing to 

reduce the likelihood of dangerous red light violations, while also 

minimizing delays to others waiting to use the intersections.

Surrogate Safety Assessment Model

The Surrogate Safety Assessment Model (SSAM) is a new software 

tool that uses trajectories generated from traffic simulation 

models to analyze indirect indicators of the likelihood of a 

collision, including time-to-collision, deceleration rates, and postencroachment time.

Safety Assessment of Access Management Techniques

Researchers are developing algorithms to assess the safety impact 

of access management techniques such as driveway spacing, nontraversable medians, and dedicated turn lanes along a particular 

roadway. Those algorithms will be incorporated into an access 

management safety evaluation tool to help practitioners evaluate 

access management needs along a specific highway and develop 

alternative access management approaches.

Pedestrian

Eleven percent of roadway fatalities are pedestrians.1

Evaluation of Pedestrian/Bicycle Safety Measures

The objective of this project is to determine the effectiveness 

of new and innovative countermeasures, including the HAWKbeacon signal, rapid-flash beacon, and shared-lane markings, 

in reducing pedestrian fatalities and injuries and in minimizing 

conflicts between pedestrians and motor vehicles.

The FHWA Office of Safety Research and 

Development (R&D) is helping to reduce highway 

crashes and related fatalities and injuries by 

developing and implementing safety innovations 

through a program of nationally coordinated 

research and technology. Selections from this 

broad research portfolio are highlighted below.

www.tfhrc.gov/safety

Office of Safety R&D

Federal Highway Administration  TURNER-FAIRBANK HIGHWAY RESEARCH CENTER
HRT-08-025

HRDS-05/09-08(2M)E

Measures of Pedestrian Exposure to Risk

Effectively assessing pedestrian safety 

requires information on pedestrian 

exposure to risk. This is typically defined 

as the ratio of crashes to total exposure. 

Vehicle exposure is represented by million 

vehicle miles traveled. However, currently 

no analogous pedestrian exposure metric 

exists. In this project, TFHRC human 

factors researchers are examining pedestrian 

crossing behaviors at seven different facility 

types that are used by both pedestrians 

and vehicles (e.g., intersections, midblock 

crossings, parking lots) to develop a new 

pedestrian exposure metric. 

Speed Management

Speeding plays a role in 31 percent of roadway fatalities.1

Effect of Urban Street Environment on 

Operating Speeds

Research indicates that more than 75 

percent of drivers claim to drive at speeds 

appropriate to the roadway regardless of 

posted speed limits. However, a driverselected speed may not correspond with the 

speed the road was designed around. In this 

program, researchers developed methods 

for estimating operating speeds based on 

drivers’ perceptions of design features, environmental factors, and operational conditions on low-speed urban roadways. 

Typology of Speeding-Related Crashes

Speeding—exceeding the speed limit or 

going too fast for conditions—is a contributing factor in many severe crashes. In this 

project, researchers are analyzing crash 

data to learn what speed-related crashes are 

like and to identify where they occur most 

often, when they are most likely to happen, 

and who is most likely to be involved in 

these crashes. The results will help highway 

agencies identify ways to reduce the number 

and severity of speed-related crashes.

Demonstration and Evaluation of Speed 

Management on Main Roads in Rural 

Communities

In many rural communities, the main road 

that runs through town is a state or county 

highway with high speed limits outside of 

the city boundaries. Motorists often do not 

slow down when they enter the center of 

town. Because traffic calming measures such 

as enhanced signing, lane width reduction, 

pavement markings, and gateway structures 

are known to work in larger urban areas, 

in this program researchers evaluated the 

effectiveness of such traffic calming treatments for reducing speeds on main roads in 

rural communities.

Evaluation of Speed-Activated Displays on 

Curves

Speeding and curved roadways are a 

dangerous combination. Many run-offthe-road fatal crashes on horizontal curves 

are speed related. This project is a national 

field test of the effectiveness of low-cost, 

speed-activated Dynamic Curve Warning 

Systems (typically a speed-measuring device 

combined with a variable message sign) in 

reducing speeds and improving safety on 

horizontal curves in rural roadways.

Safety Management

Evaluation of Low-Cost Safety 

Improvements

FHWA is partnering with 26 States to evaluate low-cost safety improvement strategies 

taken from NCHRP Report 500: Guidance 

for Implementation of the AASHTO Strategic Highway Safety Plan. The effectiveness 

of many of these strategies has not been 

rigorously established previously. Beforeand-after evaluations are being conducted 

at sites where these strategies have been 

previously implemented, and additional 

evaluations are planned for future sites. 

FHWA’s Highway Driving Simulator is also 

being used to help determine the effectiveness of these safety strategies. 

Highway Safety Information System

The Highway Safety Information System 

(HSIS) is a safety database in which accident, roadway inventory, and traffic volume 

data are combined to help users study current highway safety issues, direct research 

efforts, and make the best possible decisions 

about safety improvements. Presently, seven 

States and two urban centers are actively 

providing data to be entered into the system. Data from the HSIS have been used to 

study the safety effects of converting rural 

two-lane roadways to four-lane roadways, 

the relationship of median width to safety, 

the safety of lighting options on urban freeways, and many other safety topics. 

Interactive Highway Safety Design Model

The Interactive Highway Safety Design 

Model (IHSDM) is a suite of software tools 

for evaluating the safety and operational 

effects of geometric design decisions 

on two-lane rural highways. IHSDM is 

available as a download. The Geometric 

Design Laboratory within the Office of 

Safety R&D provides technical support 

to IHSDM users. Ongoing research and 

development will enhance and expand the 

capabilities of IHSDM, in coordination 

with the Highway Safety Manual being 

developed by the Transportation Research 

Board. 

SafetyAnalyst

SafetyAnalyst, a software package with 

state-of-the-art tools, is being developed to 

correspond to the six main steps in highway 

safety management: (1) network screening 

to identify sites and corridors that hold the 

most potential for reducing crashes, (2) 

diagnosis of safety problems at specific sites, 

(3) selection of appropriate countermeasures, (4) economic appraisal of candidate 

improvements, (5) priority rankings for 

candidate improvements, and (6) beforeand-after evaluations of safety improvement 

projects.

Advanced Research

Real-Time Pedestrian Detection System

The research objective of this project is to 

develop an on-board, sensor-based system 

that detects and tracks pedestrians and 

other objects on or near roadways during 

day and night from a moving vehicle and 

then warns drivers of potential collisions. 

Driver Visibility Requirements

The purpose of this human factors project is to examine the kind and amount of 

information that a driver needs to drive 

safely at night. The results will help guide 

road designers in their selection of roadway 

delineation and traffic control measures. 

Moreover, the results will be used to refine 

a control model for a robotic vehicle so that 

the vehicle will respond as much as possible 

like a human driver to the available pavement markings, signs, and other cues that 

human drivers use. The “final exam” for 

the control model will be the robotic vehicle 

and a human-controlled vehicle driving 

along the same section of a test track.

Digital Highway Measurement System

FHWA’s Digital Highway Measurement 

System (DHMS) is an instrumented vehicle 

which uses multiple sensors to collect a 

range of data, including roadway and roadside geometries, roadside inventories, and 

pavement condition information, all located 

very precisely. Information is collected in 

one pass and at highway speeds. DHMS 

provides data for enhanced safety analysis 

capabilities to support a State’s safety decisions, as well as to meet asset management 

needs including the data elements established by the Model Minimum Inventory of 

Roadway Elements (MMIRE). 

1 NHTSA FARS 2006 Annual Report.