Impacts of a Vehicle Inspection and Trip Permit Program on Vehicle Operations and Equity

Jennifer Dill, Portland State University


Like most states, Oregon has a vehicle inspection program (VIP) to help meet air quality standards. Vehicles in the Portland and Rogue Valley areas must pass the test to get a certificate required to register the vehicle. Owners of vehicles that do not pass the test prior to their registration expiring can obtain a short-term "trip permit." Trip permits provide vehicle owners a legal way to drive their vehicles after failing an emissions test, but before making the repairs to pass the test and renew their registration.

Starting January 1, 2002, the State implemented significant changes to the trip permit system. The State now issues no more than two 21-day permits in a 12-month period to any vehicle. In addition, the new system tracks the permits via a computer database. Previously, a vehicle owner could get a permit for up to 120 days in a 12-month period, and the permit records were not computerized. Therefore, owners could purchase successive permits with little or no chance of being caught. There was a belief that ousing trip permits to avoid registering vehicles when they failed a vehicle emissions test. 

Project Details

Project Type:
Project Status:
End Date:
March 31,2005
UTC Grant Cycle:
non-UTC research