Effects of Raising Load Limits on Pavements and Bridges in Indiana

Indiana's present weight limits for trucks arc 18,000 Jbs. on a single axle, 32,000 lbs. on a tandem axle and 73,280 lbs.gross vehicle weight.Many states have increased their weight limits to 20,000 lbs. on a single axle, 34,000 lbs. on a tandem axle and with gross limits of 80,000 lbs.This study was conducted to determine possible economic impacts on maintenance of Indiana highways and bridges if weight limits were to be increased in Indiana.Extensive use was made in this research of work reported by other investi- gators.The road life records of the Indiana State Highway Commission were searched and pavement sections were evaluated using these data coupled with truck weight information from the weight stations, soil information and performance data on file in the JHRP offices.