As streetcars make a comeback in cities across America, they are under scrutiny from transit advocates who complain about service quality.

Atlanta’s new streetcar has produced disappointing ridership numbers, with sources reporting it’s not much faster than walking. And Yonah Freemark at the Transport Politic reports that after a fairly strong start, Seattle’s South Lake Union streetcar has seen ridership sputter, with a 7 percent decline in the last year.

But the good news is Seattle has zeroed in on a key issue with the line. Freemark reports:

The problem may have something to do with the way the streetcar runs: In the street, sharing lanes with cars. The results have been slow vehicles — the line’s scheduled service averages less than eight miles per hour — often held back by traffic and a lack of reliability. This can produce horror stories of streetcars getting stuck for half an hour or more behind other vehicles and, combined with infrequent service, it certainly reinforces the sense that streetcars are too slow and unreliable to provide any serious transportation benefit.

This is a problem shared by every existing and planned modern streetcar line in the country, suggesting that the streetcar designed to run in the street with cars may, over the long term, simply fail to attract riders who grow increasingly frustrated with the quality of service provided.

Seattle may offer a solution, however. CityLab‘s Nate Berg reported last year that the city is planning a new streetcar line — the 1.1-mile Center City Connector that in 2018 would run along dedicated downtown lanes as it links the South Lake Union line with another service, the 2.5-mile First Hill line, which is currently under construction. That’s great news, but even more interesting is the fact that the city is considering giving dedicated lanes to the existing South Lake Union line.

A dedicated lane won’t address other factors that can hinder streetcar service, like long headways, frequent stops, lack of signal priority. But if Seattle proceeds with the reconfiguration it could be a model for other streetcar cities.

Elsewhere on the Network today: Rebuilding Place in the Urban Space says transit riders don’t always prefer light rail to buses. Systemic Failure peeks in on what Florida officials are calling the “ultimate” highway widening. And Transit Blogger reports there’s no state or federal plan to help New York City’s MTA with its $15 billion budget gap, even as the system sees rising ridership and overcrowding.