Each of the five MAX and 12 of the bus lines are designated as "Frequent Service" lines, scheduled to operate at headways of 15 minutes or less for most of the service day (service is less frequent in the early morning and late evening).

The bus system includes 17 transit centers, that allow passengers to transfer between bus routes and, at many transit centers, MAX routes.

Tri Met buses began carrying bicycles on the front in 1992, on a trial basis on eight routes; Each rack can hold two bikes.

Tri Met runs the MAX Light Rail (short for Metropolitan Area Express) system, and contracts with Portland and Western Railroad to operate the WES Commuter Rail line (short for Westside Express Service).

Fares on MAX (as well as WES) are the same as Tri Met bus fares, and fare collection uses a proof-of-payment system (or honor system) with ticket vending machines at each station. Incidents of violence on the system have led to calls for more security, and some have argued that more thorough checking of fares would improve riders' overall feeling of safety.

Instead, Globe Sherpa will take a commission on every ticket sale through the app.

An e-fare system named "Hop Fastpass" is being developed by Tri Met, the City of Portland, and C-TRAN that will enable riders to pay with a fare card, near field communication–equipped smartphone, or credit card, using card readers on buses and train platforms.

Tri Met, more formally known as the Tri-County Metropolitan Transportation District of Oregon, is a public agency that operates mass transit in a region that spans most of the Portland metropolitan area in the U. Tri Met started operating a light rail system named MAX in 1986, which has since been expanded to 5 lines that now cover 59.7 miles (96.1 km), as well as a commuter rail line in 2009.

Created in 1969 by the Oregon legislature, the district replaced five private bus companies that operated in the three counties; Multnomah, Washington, and Clackamas.

Tri Met does not currently operate any 60-foot (18 m) articulated buses.

However, the Powell–Division Transit and Development Project, a bus rapid transit line currently under development and projected to open in 2020, would add 60-foot (18 m) articulated buses to the Tri Met fleet.

Long-range transportation planning for the metropolitan area is provided by Metro, an elected regional government.