This post originally appeared on Orphan Road.

One infrastructure upgrade that’s going to have a big impact is the Mercer Corridor Project, which I’m reminded of in reading this Crosscut piece on the new South Lake Union park.

The goal of the Mercer project is to make Mercer a two-way street and thus avoid the traffic snarl of cars trying to get off of I-5 headed to Seattle Center. The project will come in two phases: in the first, Mercer will be come two-way only in South Lake Union. This will happen in the next two years and basically make Valley Street near the park more pedestrian-friendly (and, some have argued, add appease Vulcan, whose properties abut the park). The city’s currently buying back land from Vulcan to complete this phase.

Later, while the Viaduct is being replaced, the section of Aurora Avenue just north of Denny Way will be lowered, re-connecting the street grid between South Lake Union and Seattle Center. (As someone who walks between these areas frequently, it can’t happen soon enough. Walking between Seattle Center and SLU, no matter which route you take, is an awful blend of car exhaust, concrete, and noise. And not the good, I-live-in-a-city kinda noise. The belching-of-truck-engines-roaring-past-you-and-the-iPod-can’t-go-loud-enough kinda noise. )

Unfortunately, what’s going to happen, it seems, is that it’s going to get worse before it gets better. Making Mercer two-way without the added street-grid connections between it and Denny will probably just end up putting more congestion onto Mercer itself. We won’t see the benefits of the new arrangement until… well, until we figure out what do do with the Viaduct, and then do it. In other words, not for a while.