Civil and Environmental Engineering


Date of this Version



Poster Presented at University of Nebraska-Lincoln Research Fair, April 4-5, 2017


Copyright (c) 2017 Jianan Zhou.


Issue on level freeway segment (Interstate 80) in Nebraska: • High truck percentage (higher than 25%) • Different speed profile - The speed of trucks are set to 67 mph, on average. - The speed of passenger cars are 75 mph, on average. • Result platoons - Approximately 85% of vehicles are observed in platoon. - the degree of freedom to maneuver for drivers are constrained by other in-platoon vehicles. - Vehicles in platoons may face unsafe situation. Goal: Develop indicators to assess the safety status of vehicles under platoon conditions at level freeway segment.

The data were collected at 13 sites on Interstate 80 between Lincoln and North Platte in western Nebraska. 48,903 vehicles are observed in total, including 14,231 trucks.

1) The recommended indicators for assessing safety status include vehicle speed, length, taken-up space, the speed difference, headway and gap between leading and following vehicles on the same and adjacent lane, and the platoon types that vehicles impeded in.

2) A set of logit models with cluster groups as dependent variable and with indicators above as independent variables could be developed, and then the cluster group to which the vehicle belongs could be predicted, and the corresponding safety status could be delivered to drivers.