Occupancy for different trip purposes is only one aspect of capacity utilization; one must also consider differing trip lengths by trip purpose. The following chart shows total annual seat miles of unused capacity per vehicle for different trip types. So while only 16% of total trips nationwide are commute trips, they represent 33% of total seat-miles of unused vehicle capacity (and 46% of peak period seat-miles of unused vehicle capacity). This reinforces the previous belief that ridesharing initiatives should focus on commute-based trips. However, one should also consider the differing values of time that users place on different trip types. Commute trips are likely to have a higher value of time for most drivers, thereby making any inconvenience or delay in their journey incredibly onerous. If ridesharing is to be improved during the commute, convenience for drivers and passengers, and minimal delays are essential.