Improvements make MAX more resilient in face of extreme heat, though riders should plan ahead

Summer is here — and in Oregon, that can mean extreme heat that affects how TriMet operates.

While our climate is mild for much of the year, summer heat is no joke. Since 2020, temperatures have hit 100 degrees in Portland 20 times — all between June and September. Earlier this month, even before the official start of the summer season, we saw high temperatures reach the mid-90s.

At TriMet, we’ve been working to improve how our MAX and WES trains perform on hot-weather days. That means fewer delays and more reliable rides, even when temperatures are well into the 90s.

Even so, when temperatures climb to the triple digits, TriMet may limit train speeds for safety. Furthermore, sun and heat exposure can be dangerous, especially for children, seniors and people with medical conditions. Shade is not available at all of our stops and stations. Riders should check trimet.org/alerts, plan for trips to take extra time and have a way to keep cool during extreme heat.

Slowing down for safety

Metal expands when it’s hot. That causes sagging in our overhead wires that supply power to MAX trains. It can also cause “sun kinks” or warping in our rails. We closely monitor track conditions when temperatures rise, keeping riders safe and allowing our maintenance crews to promptly address any issues we see on our system.

We’ve been working to improve how MAX and WES perform in high temperatures. That includes upgrading the tensioning system we use to keep the overhead wires taut, as well as improving the track itself to be more resistant to sun kinks. Just this year, we installed automatic tensioning devices along a section of the MAX Blue Line, which we’re evaluating for a wider rollout.

At or above 100 degrees, we limit MAX trains to 35 mph. While trains travel below that speed on most sections of our MAX system, slowdowns can cause delays of up to 30 minutes throughout our system.

WES trains are limited to 40 mph at or above 100 degrees, which can mean 10-minute delays.

WES will not operate if temperatures reach 105 degrees. At around 110 degrees, we may temporarily suspend MAX service for the safety of our riders and employees. Buses will continue to operate, and shuttle buses will provide temporary service along WES and MAX lines if necessary.

Limiting speeds helps protect our vehicles, trackway and sensitive equipment during extreme heat. It also makes it easier for operators to keep an eye out for any heat-related issues.

Learn more about how we’re improving our system at trimet.org/heat.

How you can beat the heat

All TriMet vehicles are air-conditioned. However, shade may not be available while you wait for your vehicle, depending on where you catch the bus or MAX.

Take steps to keep cool and stay hydrated, especially when travel may take longer. Wearing sun protection and carrying an umbrella to provide shade are good ideas. So is packing a water bottle.

Remember our Rules for Riding: Drinks, such as water, coffee, tea, sports drinks and soft drinks, can be brought on board TriMet vehicles in closed containers. That includes bottles, travel mugs and cups with a lid.

Fans, umbrellas and personal sun shades are also allowed on TriMet, as long as they can be folded up or stowed. Please make sure not to block aisles or doors with any item you bring on board.

Even on unusually hot days, like the heat wave we experienced earlier this month, temperatures may not climb high enough to cause service delays. All the same, TriMet is staying prepared this summer. You can be prepared, too! Check trimet.org/alerts for the latest service information before you go. You can also sign up to receive service alerts at trimet.org/email.