TriMet prepares for the summer’s hottest weather


With temperatures expected to reach 100 degrees this week, TriMet is preparing to minimize heat-related impacts to service. Extra maintenance crews will be on stand-by to assist with overheating buses, or track and overhead power wire issues.

High temperatures affect the MAX system in two ways: the overhead power wire may sag a bit and rails may expand, so trains slow in higher speed sections to ensure the wire and the rails are not damaged.

When temperatures rise into the 90s, trains traveling in speed zones above 35 mph will need to run 10 mph slower. This will impact some segments of each of the MAX lines and create minor delays to service.

If temperatures climb above 100 degrees, trains cannot go faster than 35 mph, resulting in delays throughout the system. Riders should expect delays up to 15 minutes.

Riders should allow extra time for their commute, stay hydrated and check for service alerts before they head out into the heat.

Plan ahead

TriMet’s online trip planner is an easy way to plan a trip, with information on travel and walk times, transfers and cost. Visit or on smartphones.