TriMet's next disruptive repair project begins April 30, and the agency is warning riders that they might not want to buy their usual monthly pass.

Passes for May go on sale Thursday, but the repair work, along Southwest Yamhill and Morrison streets, will leave a MAX service gap in downtown Portland for three weeks through May 20.

Shuttle buses will run from Providence Park along the transit mall and to Rose Quarter, but TriMet is asking riders to consider alternatives to MAX, including its bus service, and to avoid bringing bulky items like bikes, suitcases and strollers on trains.

All MAX trains will run less often, meaning riders can expect longer waits and crowded cars.

Those who do take MAX, however, should expect to tack on 30 to 45 minutes to their trips, the agency said.

Portland Streetcar service also will be disrupted along Southwest 10th and 11th avenues for two weeks, from April 30 through May 13.

The work along Southwest Morrison and Yamhill streets will upgrade some of the oldest sections of MAX tracks by replacing underground wooden ties, the track be and switch machines, as well as sections of the track itself.

-- Elliot Njus

enjus@oregonian.com

503-294-5034

@enjus