Traffic speed limit in the United States.

National Highway Traffic Safety Administration, Washington, D.C.

Methods for reducing large speed differences in traffic streams. Volume I - inventory of methods. Task A report.

Federal Highway Administration, Office of Safety and Traffic Operations Research and Development, Washington, D.C.

Speed prediction for triggering vehicle activated signs

Accurate speed prediction is a crucial step in the development of a dynamic vehcile activated sign (VAS). A previous study showed that the optimal trigger speed of such signs will need to be pre-determined according to the nature of the site and to the traffic conditions. The objective of this paper is to find an accurate predictive model based on historical traffic speed data to derive the optimal trigger speed for such signs. Adaptive neuro fuzzy (ANFIS), classification and regression tree (CART) and random forest (RF) were developed to predict one step ahead speed during all times of the day. The developed models were evaluated and compared to the results obtained from artificial neural network (ANN), multiple linear regression (MLR) and naïve prediction using traffic speed data collected at four sites located in Sweden. The data were aggregated into two periods, a short term period (5-min) and a long term period (1-hour). The results of this study showed that using RF is a promising method for predicting mean speed in the two proposed periods.. It is concluded that in terms of performance and computational complexity, a simplistic input features to the predicitive model gave a marked increase in the response time of the model whilse still delivering a low prediction error.

Evaluation of factors affecting speed perception in a driving simulator

The present study was conducted to determine the effects of different variables on the perception of vehicle speeds in a driving simulator. The motivations of the study include validation of the Michigan Technological University Human Factors and Systems Lab driving simulator, obtaining a better understanding of what influences speed perception in a virtual environment, and how to improve speed perception in future simulations involving driver performance measures. Using a fixed base driving simulator, two experiments were conducted, the first to evaluate the effects of subject gender, roadway orientation, field of view, barriers along the roadway, opposing traffic speed, and subject speed judgment strategies on speed estimation, and the second to evaluate all of these variables as well as feedback training through use of the speedometer during a practice run. A mixed procedure model (mixed model ANOVA) in SAS® 9.2 was used to determine the significance of these variables in relation to subject speed estimates, as there were both between and within subject variables analyzed. It was found that subject gender, roadway orientation, feedback training, and the type of judgment strategy all significantly affect speed perception. By using curved roadways, feedback training, and speed judgment strategies including road lines, speed limit experience, and feedback training, speed perception in a driving simulator was found to be significantly improved.

Statistical models of accidents on interchange ramps and speed-change lanes.

Federal Highway Administration, Office of Safety and Traffic Operations, Washington, D.C.

Speed control on high speed roads. Final report.

Federal Highway Administration, Traffic Systems Division, Washington, D.C.

The development of a speed monitoring program for Indiana.

Indiana Department of Transportation, Indianapolis

Speed and accidents. Phase 1. Interim report.

National Highway Safety Bureau, Washington, D.C.

Speed zoning and control. Final report.

Texas State Department of Highways and Public Transportation, Transportation Planning Division, Austin

The safety impact of the 65 mph speed limit: a case study using Alabama accident records. Final grant report.

National Highway Traffic Safety Administration, Office of Research and Development, Washington, D.C.

Computerized allocation of police traffic services; a demonstration study. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Computerized allocation of police traffic services; reference volume I. Computer-sensor system description. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Highway safety : monitoring practices to show compliance with speed limits should be reexamined.

"B-229461"--P. 1.

Accident and speed studies in construction zones. Final report.

Federal Highway Administration, Office of Research and Development, Washington, D.C.

A Novel Framework for Real-time Traffic Flow Parameter Estimation from Aerial Videos

Thesis (Master's)--University of Washington, 2016-06