Truck Acceleration Speeds and Distances at Weigh Stations

• Published in: Transportation research record 2010-01, Vol.2195 (1), p.20-26
• Main Authors: Gattis, J. L., Bryant, Micah A., Duncan, Lynette K.
• Format: Article
• Language: English
• ISSN: 0361-1981; 2169-4052
• DOI: 10.3141/2195-03

Tractor-trailer trucks accelerating on freeway entry ramps and entering the main traffic lanes require greater lengths to accelerate than do passenger vehicles. As freeway volumes have grown over the decades, entry ramp junction designs that were once adequate now experience congestion at weigh stations and other locations where higher volumes of trucks enter the freeway. The acceleration lengths and speeds of tractor-trailers accelerating onto freeways were measured at five vehicle weigh stations. Other data obtained and analyzed included truck weights, freeway volumes, and freeway grades. Models were developed to predict tractor-trailer speed over given acceleration lengths. From the analysis, it was concluded that longer acceleration lanes were needed for heavy vehicles leaving weigh stations to accelerate to speeds closer to the speeds on the main lanes and to be less disruptive to freeway traffic flow as the heavy vehicles merge into the main lanes. The findings also have implications for establishing the location of weigh stations, the spacing of freeway interchanges, and the setting of freeway speed limits.