Winter Weather Resources for Media

Bus Passing Park Block with Kids PlayingThis is a resource page for the media during a winter weather event.

It provides insight into TriMet’s operations during inclement weather and has tips to share about riding transit during snow and ice. For service alerts, go to Call the TriMet media duty pager for additional information or to request an interview.


Safety over Schedules

During inclement weather, TriMet plays a critical role in helping to keep the region moving. We want to get riders safely to their destinations so during winter weather conditions our most important principle is Safety over Schedules: If it’s not safe for our operators, riders or equipment, TriMet will alter service. That may mean putting a bus line on snow route, altering a route or canceling a limited run line entirely. View snow routes.

Partnering to Keep Transit Moving

Snow Plow Lead Line 20 BusTriMet partners with the Oregon Department of Transportation, the City of Portland and jurisdictions throughout the region to help keep transit moving during a storm. TriMet has worked with these partners to identify priority streets for snow plowing that include our busiest bus routes. View priority bus lines during severe ice and snow.

TriMet managers and operations staff closely monitor weather reports as a storm moves in, and coordinate with local partners to keep the roads open so buses and trains can operate. We have employees working around the clock to chain buses, prepare equipment and assess higher elevation routes. TriMet even has a few of its own sanding trucks to augment the resources of our local and state transportation partners.

Emergency Operations Center
DSCN0117 During major weather events, TriMet activates an Emergency Operations Center (EOC). It is staffed 24/7 during an event. TriMet’s EOC coordinates with city, county and state EOCs to assess the status of the region’s roads and operations, and identify needed resources. We also assign personnel to the Portland Bureau of Transportation’s EOC to increase communication and identify street plowing priorities.

During a snow or ice event, TriMet crews will go out before service begins for the day to assess bus routes in higher elevation areas. They determine if it is safe to operate regular routes or if any routes need to be altered. These “snowbirds” as we call them coordinate with city crews for sanding needs. They may also call for a TriMet sanding truck. TriMet has three sanding trucks – one assigned to each of our bus maintenance facilities. We augment city sanding efforts in key spots as needed to keep the buses moving.

Bus service
TransitMallBuses face the same road conditions as other vehicles. If streets become impacted by snow or ice, buses will run slower and can be delayed. If it is not safe for our operators, riders or equipment, TriMet will alter service.

TriMet crews focus on getting service on the street. For that reason, we no longer allow media to record chaining operations. View a bus chaining operation. Call the duty pager to request a copy of the video in broadcast quality.

Fast Facts

  • TriMet now has about 304 buses – or nearly 50 percent of our fleet – equipped with automatic drop-down chains. The operator deploys the chains with a push of a button when extra traction is needed. These are the same type of chains used on many school buses. While the drop-down chains are not for use during heavy snow, they will improve traction during most of the snow storms we experience in the TriMet service district. This will also give us time, should there be a sudden change in the weather, to continue those buses in service while crews begin installing the more heavy-duty chains on other buses. View drop-down chains in action. Call the duty pager to request a copy of the video.
  • Depending on the forecast, either a portion of the bus fleet will be chained by maintenance workers or the entire fleet will be chained. Chaining takes place at each of TriMet’s three garages. It takes 10 minutes to chain a bus at the garage or 15 minutes in the field. It takes eight to 10 hours to chain entire fleet. View TriMet’s standard bus chains. Call the media duty pager to request a copy of the video in broadcast quality.
  • Buses with chains can travel at a maximum of 25 mph, which means buses will not be on schedule, but the aim is to keep them moving and doing so safely.
  • In extreme cold temperatures, buses may idle overnight to keep engines warm and prevent air systems from freezing. Brakes, doors, wipers and starters are all air operated.
  • During snow and ice, operators are trained to not pull to the curb because of the possibility that the bus may slide or become stuck. See Tips for Riders.
  • Bus rescue teams are on standby and are deployed to get stuck buses moving again, repair or replace broken chains or chain buses in the field. TriMet also has on-call contracts with towing companies to assist further.

MAX service
Waiting for MAX 2008 - AMAX typically does very well in the snow. However, during major weather events trains may be delayed by automobile traffic in sections where vehicles cross the tracks, such as in downtown Portland.

Fast Facts

  • The MAX system has rail-switch covers, most with heaters, to prevent snow and ice accumulation on the switches.
  • Ice caps, hard plastic caps that covers a portion of the overhead wire, are along all MAX lines east of the Willamette River and at both rail yards.
  • All trains are outfitted with pantograph heaters, which are activated when there is frozen precipitation to help prevent ice buildup on the lines. (The pantograph is the arm that reaches from the top of the train to the overhead power line; the heaters help keep the pantograph’s contact point warm, helping prevent ice build-up.)
  • If necessary, four to six trains will run after normal operating hours on the entire 60-mile system to keep the overhead power line from accumulating ice. If riders are at the station during these off hours, we will allow them to board.
  • Six light rail vehicles have heated ice cutters installed that can shave approximately 1/32 inch of ice off of the power wire. The cutters are mounted on a second pantograph and can be raised and lowered as needed. Speed is restricted to 35 mph for the trains outfitted with ice cutters. They can make two round trips around the system before the ice cutters need to be sharpened.

Platforms, transit centers, garages, parking lots

Anti-icing liquid, Calcium Magnesium Acetate (CMA), is applied on platforms, at transit centers, garages, parking lots and other places prone to ice buildup. It is the same liquid that ODOT, the Portland Bureau of Transportation and other transportation agencies in the region use for roads and bridges. The fluid prevents ice and snow from bonding to the surface, but it has to be applied to a dry surface before snow or ice falls. CMA is environmentally friendly – it biodegrades to carbon dioxide and water. It’s safe for vegetation and non-toxic to water species.

Tips for Riders

During snow and ice, TriMet often sees riders new to the system. It is always important for riders to check before they go for service alerts and be prepared for the winter weather.

  • Expect delays.
  • Dress warmly and stay visible: wave to the operator and carry a small flashlight or strobe.
  • Wait on flat ground: if your bus stop is on a hill, walk to the bottom or top as the bus cannot stop on a slope.
  • Stand on the curb until the bus comes to a complete stop. Buses may not pull up to the curb in order to prevent damaging chains and/or getting stuck, so you may have to step into the road to board.
  • Check the status of a bus or train before you leave the house by visiting
  • During snow or ice conditions, buses and trains may get so far off their normal schedule or route that TransitTracker can’t predict real-time arrivals accurately. When this happens, we may turn TransitTracker off completely. However, riders can still get service and snow route updates on the’s Service Alerts page.

Quick Links

Check for service alerts
View snow routes
Learn about the service plan for severe weather
Get more rider tips for inclement weather