U.S. Route 31 in Indiana - Route Description

Route Description

Only the segment of US 31 that is north of Indianapolis is included as a part of the National Highway System (NHS). The NHS is a network of highways that are identified as being most important for the economy, mobility and defense of the nation. The highway is maintained by the Indiana Department of Transportation (INDOT) like all other U.S. Routes in the state. The department tracks the traffic volumes along all state highways as a part of its maintenance responsibilities using a metric called average annual daily traffic (AADT). This measurement is a calculation of the traffic level along a segment of roadway for any average day of the year. In 2010, INDOT figured that lowest traffic levels were the 3,690 vehicles and 160 commercial vehicles used the highway daily near Memphis. The peak traffic volumes were 168,770 vehicles and 18,090 commercial vehicles AADT along the section of US 31 concurrent with Interstate 465 (I–465).