Exploratory Advanced Research . . . Next Generation Transportation Solutions

Field Experiments

The study will see field experiments conducted in 

the Miami, Orlando, and Atlanta metropolitan areas. To secure reliable statistics, the research will 

involve 200 to 300 drivers per metropolitan area, 

with participants selected in partnership with the 

toll authorities. The research team plans to equip 

the private vehicle of each participant with a GPS 

device to observe the participant’s daily driving 

choices as road prices are manipulated for various 

routes and departure times. Choices presented to 

the driver during the experiment will involve routes 

they frequently travel, and data will be gathered 

only on select routes that match an important attribute set, making inferences more accurate and 

precise. The research will investigate how the 

route and departure time choices relate to personal attributes such as risk attitudes, age, and gender. 

This data will infer the value of time to researchers, 

a crucial piece of information in predicting how 

drivers will react to congestion pricing schemes.

Simulation Experiments 

Each participant will also be engaged in drivingchoice experiments in a lab environment using 

driving and traffic simulations. These simulations 

will complement the field experiments, allowing 

identification of individual characteristics that are 

otherwise not observable. To provide realistic experiences in a portable environment, the study 

uses L3-MPRI Driving Simulation Software on portable computers, equipped with steering wheels 

and gas and brake pedals. Subjects will be able to 

choose one of two simulated routes: either a nontolled route with uncertain congestion conditions 

or a tolled route with free-flow traffic. As researchers manipulate various economic incentives, including tolls, and observe how congestion varies 

over time, multiple participants will make route 

choices simultaneously and generate congestion 

conditions.

The Exploratory Advanced Research Program Fact Sheet

Evaluating Behavior

The study will examine how experimental economics can change transportation engineering by enabling the evaluation of behavioral responses that 

are difficult to predict and yet have strong influences on the effectiveness of engineering solutions. 

Experimental economics allows careful control of 

the process by which drivers participating in the 

study respond to alternative route and price options. Because congestion conditions are uncertain 

and differ across routes and departure times, the 

study will use estimated decision models—defined 

using criteria such as travel time, purpose, and value of trip—as well as various costs and benefits related to arrival times. Several congestion pricing 

schemes will be tested, and driver decisions will be 

collected through field and simulated conditions in 

a laboratory environment. The outcome of the study 

will be a set of prediction models expected to be a 

valuable contribution to the traffic planner’s toolbox, 

in addition to a manual for conducting similar congestion pricing experiments.

When and why drivers choose a priced or tolled facility over an untolled but congested parallel route is the 

subject of 3-year project funded by the 

Federal Highway Administration’s (FHWA) 

Exploratory Advanced Research (EAR) Program, in partnership with the University of 

Central Florida and Georgia State University. “Experiments on Driving under Uncertain Congestion Conditions and the Effects 

on Traffic Networks from Congestion Pricing Initiatives” will examine how driver’s 

risk preferences influence their choice of 

route and travel departure time.

Investigating Congestion and Solutions 

Experiments on Congestion Conditions and Pricing Initiatives
Moving Forward

The research team has already completed the design of the field and simulation experiments, and 

established coordination with different agencies in 

the three regions where data collection will occur. 

Preliminary tests of the procedures are underway, 

and full-scale pilot experiments will be conducted 

later this year. “The first major report of the study is 

a guide to the application of experimental economics in the area of congestion pricing,” explains Karen White at FHWA. “The key purpose of the guidebook at the end of the report will be to provide 

detailed instructions to illustrate the most effective 

manner in which to inform subjects about the experiment and will offer explanations of the type of 

statistical analysis that should be undertaken to 

draw valid inferences. This should ultimately prove 

to be a valuable reference tool.”

Learn More

For more information on this EAR Program project, 

contact Karen White at FHWA, 202-366-9474. 

(email: karen.white@dot.gov).

What Is the Exploratory 

Advanced Research Program?

FHWA’s Exploratory Advanced Research (EAR) 

Program focuses on long-term, high-risk research with a high payoff potential. The program addresses underlying gaps faced by applied highway research programs, anticipates 

emerging issues with national implications, 

and reflects broad transportation industry 

goals and objectives. 

To learn more about the EAR Program, 

visit the Exploratory Advanced Research Web 

site at www.fhwa.dot.gov/advancedresearch. 

The site features information on research solicitations, updates on ongoing research, links 

to published materials, summaries of past EAR 

Program events, and details on upcoming 

events. For additional information, contact David Kuehn at FHWA, 202-493-3414 (email: david.kuehn@fhwa.dot.gov), or Terry Halkyard at 

FHWA, 202-493-3467 (email: terry.halkyard@

fhwa.dot.gov).

Investigating Congestion and Solutions 

Experiments on Congestion Conditions and Pricing Initiatives

Publication No. 

FHWA-HRT-10-061

HRTM-04/06-10(1M)E

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