PORTLAND, Ore. — Transportation officials across Portland are preparing for a winter storm expected to bring snow and freezing rain to the region Thursday and Friday. The Portland Bureau of Transportation has been gearing up for about a week, pre-treating major roads with magnesium chloride de-icer and preparing its fleet of 56 snowplows for deployment.

Dylan Rivera, spokesperson for the Portland Bureau of Transportation (PBOT), said the top priority will be critical arterial routes needed for emergency response.

“We are laser focused for making passable routes for police, fire and ambulance providers to be able to respond to life safety emergencies throughout a winter event,” Rivera said.

However, the agency does not expect to call out its full staff due to the storm’s expected short duration. PBOT usually tries to scale its responses based on the size of forecasted winter events, though Rivera added the the agency is still “preparing for the worst and hoping for the best.”

One advantage leading up to the storm has been the dry weather, allowing pre-treatments to remain effective. If the storm had been directly preceded by a day or two of rain, it would’ve washed away the magnesium chloride or made it less effective, Rivera said.

PBOT expects to add road salt to the mix Wednesday night ahead of the storm, and will spread more as needed while snow falls. But even with dual pre-treatment, the freezing rain expected Thursday night into Friday morning is a significant concern for officials.

“If it was just a trace of snow or just an inch of snow, that might be some cause for concern, but freezing rain is just dangerous,” Rivera said. “Avoid travel until conditions improve is the best thing to do with freezing rain.”

In addition to the emergency routes, PBOT will prioritize plowing routes near shelters to ensure access remains open. However, residential and side streets will not receive treatment or plowing.

The Oregon Department of Transportation (ODOT) and Multnomah County have also pre-treated roads and are shifting to 24-hour operations to provide full coverage.

“Our crews will be working around the clock to make sure our roads are as safe as possible,” ODOT spokesperson Rian Windsheimer said. “We have our plow trucks and our salt ready to go.”

Officials urged commuters to prepare for unpredictable conditions, especially on Thursday, which is expected to start out dry but transition to snow later in the morning.

“Weather can be unpredictable,” Windsheimer said. “Don’t leave home in the morning and expect the conditions to be the same on your drive home.”

Multnomah County road maintenance supervisor Ken Bossen said that drivers who must be on the road should slow down for safety. He and Rivera also warned drivers against abandoning their vehicles in main travel lanes.

“If you do abandon your car, PBOT will ticket and tow any car left in a driving lane,” Rivera said.