A drop in riders could eliminate one-third of funding for TriMet’s Southwest Corridor Project in Portland, Ore.

TriMet’s Southwest Corridor Project could lose one-third of its funding if a measure is not approved by voters in November.

TriMet

Eliminating park-and-ride spots has TriMet officials in Portland doing a duck-and-cover. Passenger estimates for the new Southwest Corridor Project have dropped from 43,000 to 37,500. TriMet was initially planning on the higher number for the $2.8 billion project, but the new number is a reflection of less park-and-ride spots in an effort to reduce the overall cost of the endeavor and the overall impact on car traffic near MAX stations. TriMet will be building 2,000 less park-and-ride spots.

At stake is a ballot measure in November that could sink the Southwest Corridor Project if it is not approved. A third of the $3 billion transportation measure is expected to be linked to the new transit line.

This is not the first time TriMet’s ridership numbers have been off. The agency has miscalculated Orange Line ridership. First-year projections by TriMet were off by 6,000 riders. Yellow and Green lines also are struggling to meet projected numbers. The Yellow Line was expected to have 4,700 more commuters by 2020, while the Green Line is short 12,000 riders.

TriMet says transit ridership is down nationwide, and that the new Southwest Corridor will still end pulling cars from the road, especially on I-5.

The region was hoping to double its rail riders by 2040, but since 2009 the number of passengers has dropped 6 percent.

Transit experts say the one problem with the Orange Line is inadequate bus service picking people up from the main hub in Milwaukie, and TriMet might be making the same mistake with the Southwest Corridor Project, where just 23 percent of rides on the line are expected to be transfers from other forms of transit.

Up to 17 hours of daily congested is projected in the Southwest Corridor by 2035.

For the latest news, go to www.rtands.com.

More on passenger rail.