The data used in this study is drawn from the Motor Carrier Management Information System (MCMIS) database, which is maintained by the FMCSA (Cantor et al.
First, if an active motor carrier in 2014 does not appear in the MCMIS database in 2015 and 2016, it is identified as having exited.
There are 30 commodity segments reported in the MCMIS census database.
The inputs were collected from two online databases, MCMIS
and FMCSA; the highway statistics were collected from the FHWA.
Using four years of the Motor Carrier Management Information System (MCMIS) data, the number of times [each] violation group was recorded in noncrash inspections was divided by the number of noncrash inspections to produce the frequency of the occurrence of [each] violation group in noncrash inspections.
The data included all roadside inspections conducted during calendar year 2008; the data source was the Motor Carrier Management Information System (MCMIS).