Trucks are often critized for their effects on highway congestion and safety issues. However, rapid increase of freight demand justifies using heavy and long trucks, namely ultra long trucks (ULTs). If these trucks are admitted on motorways, the first ideas expect a decrease of the level of service especially at weaving sections of motorways where lane changing happens. The findings of this paper indicate that a considerable decrease in the level of service at weaving sections would not occur. This result is reliable, especially at normal rates of heavy vehicles on the weaving section areas (less than 30%). If the maximum allowable length for ULTs is equivalent to 25.25 m then the decrease of speed of weaving and non-weaving traffic would be limited to less than 3 km/h. The results also indicate that in usual conditions, namely less than 15% heavy vehicles in traffic, the minimum required length of the weaving section that is to be provided at present must be increased up to 100 m. The additional length ensures a stable level of service. (A)
Abstract