We’re often asked what happens after Orange Line trains go over Tilikum Crossing and enter Downtown Portland: Do they turn around at PSU? Do they become Yellow or Green line trains? Will I have to transfer to get to the Transit Mall?
The Orange Line will share Green/Yellow line tracks once it reaches the PSU South/SW 6th & College Station in Downtown Portland. What’s more, the Orange and Yellow lines will share vehicles — this is called interlining. Throughout most of the day, Orange Line trains heading north will continue as Yellow Line trains along their normal route.
This means a one-seat ride from Milwaukie and Oak Grove into Downtown Portland and beyond, all the way up to Expo Center.
Similarly, most Yellow Line trains headed south will continue as Orange Line trains down to the end of the line at the SE Park Ave Station. Interlining is more efficient than turning Orange and Yellow trains around Downtown; it requires fewer trains and eliminates transfers for north-south riders.
So why isn’t this a Yellow Line extension?
Separating the two lines gives us flexibility, allowing us to increase frequency on one line without affecting the other. (For example, projections of high ridership on the Orange Line mean that some of its trains will turn around at Union Station during rush hour to meet that demand.)
Looking down the road, any addition of light rail or high-capacity transit in the future — like the options Metro is studying for the Southwest Corridor — would have an effect on ridership patterns on the system. It’s possible that the difference between service frequency on the Orange and Yellow lines might become even more pronounced. As it is, we expect relatively few riders to travel between Milwaukie and North Portland; most are likely to head Downtown or transfer to east-west service.
Additionally, we think the Orange Line deserves its own recognition as a pioneering endeavor. Besides showcasing the first bridge of its kind in the U.S., the Orange Line features a host of sustainable elements like eco-roofs, eco-tracks and bioswales to capture stormwater runoff. And it serves a distinct corridor stretching from the region’s urban core to growing communities, setting it apart as our region’s newest light rail line.