David Daniel York
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
David Daniel York has a total of 3 co-authors. Here are the top co-authors by number of shared publications:
- Ahmed Jalil Al-Bayati
Lawrence Technological Univ
1 shared publication - Reza S. Shirazinejad
Department of Civil and Environmental Engineering, Kennesaw State University, 1100 S. Marietta Pkwy, R2-325, Marietta, GA 30060, USA
1 shared publication - Sunanda Dissanayake
Department of Civil Engineering, Kansas State University, 2118 Fiedler Hall, Manhattan, KS 66506, USA
1 shared publication
Latest Publications
- Open Access
- 26 December 2018
- Published by MDPI AG in Sustainability
- Vol. 11 (1) , 119
Evaluating the Safety Impacts of Increased Speed Limits on Freeways in Kansas Using Before-And-After Study Approach
In the summer of 2011, a change in the Kansas laws came into effect, increasing the speed limit on a selected set of freeway sections from 70 mph to 75 mph. Higher speeds were thought to have economic benefits, mostly because the travel time reduction means people reach their destinations more quickly. In this study, the sections where the speed limits remained unchanged, are compared to freeway sections that have been influenced by speed limit increase, to evaluate safety effectiveness. The study utilizes the before-and-after study with comparison group method to assess the safety effects provided in the Highway Safety Manual (HSM). Two crash datasets, obtained by considering three years before and three years after the speed limit increase, were compared in order to evaluate the safety effects of the speed limit change. The crash modification factors (CMFs) were estimated, which showed that there was a 27% increase in total crashes and a 35% increase in fatal and injury crashes across all sections after the speed limit change, and these increases were statistically significant at 95% confidence level. These confounding results show that the speed limit increase has not been beneficial for traffic safety in Kansas, and hence it is important to be cautious in such future situations. Also, additional data have been presented which would be beneficial in identifying and understanding any behavior change in drivers following a speed limit increase.
- 26 December 2018
- Published by MDPI AG in Sustainability
- Vol. 11 (1) , 119
Open AccessEvaluating the Safety Impacts of Increased Speed Limits on Freeways in Kansas Using Before-And-After Study Approach
In the summer of 2011, a change in the Kansas laws came into effect, increasing the speed limit on a selected set of freeway sections from 70 mph to 75 mph. Higher speeds were thought to have economic benefits, mostly because the travel time reduction means people reach their destinations more quickly. In this study, the sections where the speed limits remained unchanged, are compared to freeway sections that have been influenced by speed limit increase, to evaluate safety effectiveness. The study utilizes the before-and-after study with comparison group method to assess the safety effects provided in the Highway Safety Manual (HSM). Two crash datasets, obtained by considering three years before and three years after the speed limit increase, were compared in order to evaluate the safety effects of the speed limit change. The crash modification factors (CMFs) were estimated, which showed that there was a 27% increase in total crashes and a 35% increase in fatal and injury crashes across all sections after the speed limit change, and these increases were statistically significant at 95% confidence level. These confounding results show that the speed limit increase has not been beneficial for traffic safety in Kansas, and hence it is important to be cautious in such future situations. Also, additional data have been presented which would be beneficial in identifying and understanding any behavior change in drivers following a speed limit increase.