TriMet News

summer

  • TriMet is prepared for summer heat — riders should be, too!

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

    Image of two TriMet MAX trains preparing to pass near the Rose Quarter Transit Center in Northeast Portland. The Steel Bridge is visible in the background.

    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.

    Image of Tensorex tensioning devices on overhead wires at the Gresham Central Transit Center. A TriMet MAX train is visible at the bottom of the frame.

    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.

  • TriMet is ready for summer season

    When temperatures reach 100 degrees Fahrenheit, expect delays on MAX and WES

    MAX Red Line train on a warm, sunny day in Downtown Portland.

    Summer is officially here!

    With warm, dry weather prevailing throughout the season, it’s the best time of the year to get out and see all our region has to offer. TriMet connects people to opportunities every day. Whether you’re going to work, traveling to an appointment or seeking fun in the sun, why not ride with TriMet this summer?

    We’ve made improvements in recent years to better weather the summer heat. On the vast majority of summer days, you can expect TriMet to provide regular service, including air-conditioned comfort on our buses and trains.

    Extreme heat, however, can affect operations and our riders. Here’s what you need to know about TriMet in hot weather.

    Triple digits means delays

    If temperatures rise to 100 degrees Fahrenheit or higher, we will restrict the speed of MAX trains in certain areas for safety.

    MAX draws power from a system of overhead wires that are sensitive to heat. We limit speeds on MAX to no more than 35 mph when it’s at least 100 degrees, to reduce the risk of damage and keep our system running smoothly. Trains already run below 35 mph in areas where they run alongside or cross other traffic. But in restricted right-of-way areas, trains travel up to 55 mph. When the speed restriction is in place due to the heat, riders should expect up to 30-minute delays on MAX.

    WES commuter trains will also run no faster than 40 mph when temperatures soar above 100-degree temperatures. This may result in delays up to 10 minutes.

    Our buses are designed to operate in a wide range of weather conditions. There is no temperature threshold at which we’ll suspend or reduce bus service across our system. However, traffic and mechanical issues caused by extreme weather can sometimes result in delays. We’ll share the latest service information online at trimet.org/alerts, as well as with riders directly via email and text updates.

    Adapting to summer heat

    We’ve been working to improve how our transit system performs in hot weather.

    MAX was originally designed to operate in the climate Portland enjoyed in the 20th century. But as our region sees more extreme weather and rising summer temperatures, we are making adaptations to keep MAX running more smoothly for more of the summer. Similarly, we’ve worked with Portland & Western Railroad to improve heat resiliency on WES.

    On the MAX system, we have re-engineered parts of our overhead wire system to reduce sagging caused by intense summer heat. Because metals like copper and steel expand when it’s hot, we have to use counterweights to keep the overhead lines taut. With the improvements we’ve made, those counterweights work better in hotter weather, so MAX can keep running at regular speeds in all but the most extreme heat.

    Since 2018, the MAX Blue and Red lines have been able to proceed at normal speeds up to 100 degrees. The MAX Yellow Line followed in 2019. Now, as of this summer, all of our MAX lines are able to run regularly up to 100 degrees.

    Operating when it’s safe

    The safety of our riders and employees during extreme weather is central in TriMet’s decision-making. Above 105 degrees, we may adjust or suspend service on MAX if conditions warrant. These decisions are made with care and will depend on the conditions we’re seeing throughout our system.

    When temperatures hit 105 degrees, we will suspend service on WES and replace trains with shuttle buses.

    While we’ve made big upgrades to keep our trains running more reliably when it’s hot, extreme weather does place an additional strain on our machinery and electronics. Be prepared for trips to take extra time.

    You can learn more about our thresholds for extreme heat by visiting trimet.org/heat.

    Line 4-Fessenden on the road on a sunny day.

    Keeping cool on transit

    TriMet buses, including LIFT paratransit vehicles, have air conditioning on board for the comfort and safety of our riders and employees. So do MAX trains, WES trains and Portland Streetcar vehicles.

    But summer heat can be dangerous! When it’s hot outside, we encourage riders to:

    • Wear sun protection.
    • Pack a water bottle or sports drink with electrolytes to stay hydrated.
    • Consider using a personal fan or mister to keep cool.
    • If possible, stay in the shade when waiting at our stops and stations. Shade may not be available at all stops and stations. Carrying an umbrella can also provide cover from harmful UV radiation and relief when it’s hot and sunny.

    You can track your bus or MAX train at trimet.org. Our real-time map shows where the vehicle is and how long before it will arrive at the stop or station. Be sure to check weather reports as well as our website, trimet.org/alerts, for service information before you head out.