Tuesday, June 06, 2006



It's easy to underestimate or dismiss the impacts the Interstate Highway System has had on our neighborhoods and downtown.

Last night, as I sat on the bus in an immense traffic jam on Washington Ave. near Tucker, I contemplated this.

Many of the streets in neighborhoods and within downtown itself near downtown serve as collectors of traffic from the Interstates. This is true both of major streets like S. Jefferson and S. Tucker, and side streets like N. 9th and N. 10th near Cochran Gardens.

But even the exit locations themselves are not straightforward nor easy to understand. Figuring out how and where to get onto westbound I-70 from within downtown is harder than it needs to be. If you're near the Arch and Old Courthouse you just head north on Memorial Drive and pick up the ramp that enters 70 about 1 block south of Washington.

(This section of I-70, between Washington and Pine, is the worst barricade of all between the Archgrounds and downtown. Not only are there no pedestrian or vehicular crossings, access into downtown is further blocked by the massive superblock of the Mansion House Center parking garage and grounds.)

The next WB on-ramp serves traffic coming from the MLK bridge. I don't think there's a way to access this ramp from within downtown.

Most central and western downtown traffic enters I-70 west at either 4th Street or 9th Street. 4th Street roughly parallels N. Broadway and serves as the northbound traffic route for Broadway within downtown.

The onramp to WB 70 comes a bit north of Biddle Street, after a confusing, winding section of road that runs next to and then under I-70. The Cole Street intersection is particularly confounding. (N. Broadway finally becomes a regular two-way street just south of Cass).

The "9th Street" on-ramp is pretty far north. Coming out of downtown, drivers pass the convention center, Cochran Gardens, Columbus Square, and Cass Ave. The corner of 9th and Howard is located on an overpass above I-70. Then, to access the on-ramp, you veer wildly to the left at about 9th and Mound. This I-70 east outer road is, confusingly, signed as 10th St.

The Madison Street exit ramp enters 10th near Tyler, and the old Interurban tracks pass over near Chambers. Then there's the stop sign at the Madison overpass, a pedestrian overpass at North Market, and finally at 10th and Benton the 9th St. on-ramp enters westbound I-70.

As a result, 9th Street in the evenings - and its twin, 10th Street in the mornings - are super-speedways where most downtown-bound commuters have little regard or knowledge about the neighborhoods through which they pass.

Of course, the worst thing about downtown traffic is that the streets within and around downtown function as connector ramps between the different highways. This is partly because the North-South Collector-Distributor (I-755) was -- thankfully -- never built across Lafayette Square, western downtown, and St. Louis Place. As a result, there are no direct connections from EB Highway 40 to WB I-70, WB I-44 / SB I-55; or to WB Highway 40 from EB I-70, NB I-55 / EB I-44.

That means more wear-and-tear on city streets than expected. The S. Jefferson viaduct between Highway 40 and Chouteau carries tons of traffic. Only built in 1967, it is in dire need of reconstruction or replacement. It's amazing to me the Foodland store property can sit vacant at Lafayette and Jefferson given the huge traffic counts at that intersection.

However, many drivers on that stretch of Jefferson at peak hours are just passing through from their residences in places like far South City, South County, Columbia IL, maybe even Arnold; to employment centers in the central corridor like SLU, BJC, WashU, and maybe even downtown Clayton.

Some also are entering downtown from EB I-44, since Jefferson is still a bit more convenient than other routes like the left-side exit at Lafayette that (sort of) accesses the compromise solution to the non-building of I-755: Truman Parkway. (Prior to the construction of Truman Parkway, most people used Dolman as a cut-through between 18th/Chouteau and the on-ramps at Lafayette).

Truman Parkway, of course, has two dedicated exit lanes from NB I-55. But most traffic prefers to exit at Gravois/Russell, and trek northward on congested S. Tucker into downtown. That might change when the reconstruction of S. Tucker from Chouteau to Lafayette starts this summer.

Eventually, Truman Parkway will be extended northwest slightly, to merge into 18th Street. This is great for folks coming from the south and southwest to access Union Station and nearby office complexes. But it provides no connection to I-64. Those travelers will continue to use Jefferson, or perhaps cut over to 14th from Truman/18th via Chouteau or Clark to access the bizarre westbound I-64 on-ramp at 14th and Clark.

Another option for accessing downtown from the south (without getting caught up in the Memorial Drive mess) could be Park Avenue. Then you can enter downtown either via 7th or via Broadway/4th.

That works for some destinations, but often traffic is slow by that point on I-55 north, even in the mornings when bridge traffic shouldn't be heavy. But since I-55 north has a puny single-lane, narrow, steep on-ramp onto the Poplar Street Bridge, one slow-moving tractor-trailer can tie up the entire stretch of I-55 from there south.

Similarly, the single lane that runs from the westbound PSB onto southbound I-55 (and thence westbound I-44) is also steep and twisty. One of the most dangerous things about the westbound PSB is the traffic jockeying for lane position in that approach.

While the PSB appears to be four lanes westbound, only one of those lanes (the far right lane) connects to westbound I-70 and to downtown. Once you get onto that off-ramp, it splits so that the left ramp lane goes to 70 and the right ramp lane heads onto Memorial Drive.

The I-55/44 ramp is the second from the right lane on the PSB. And the two left lanes continue west onto Highway 40/I-64. The next exit past there is at 9th Street.

Getting to/from downtown and traveling through downtown can be tricky, indeed. And that's without any construction projects!


urban Review said...

Wow, you've really looked at all the various highway access points. But, the really sad part of this is what it has done to those of us not trying to get on the highway.

Even though we have a grid and we have tall buildings we've basically suburbanized our city. We can't fully utilize the grid to disperse traffic as we've got so many streets that are one-way or closed here and there. This leaves too few through streets which then collect all the traffic while others remain nearly empty.

Doug Duckworth said...

I appoint Joe to director of the Department of Streets!

Anonymous said...

The long-term solution is replacing both the 22nd and 14th street interchanges on Highway 40 with just one new interchange at 18th. Such solution would free up land to the west of Union Station for infill development, reduce cut-through traffic on Tucker and Jefferson, and allow 14th to be a more local road as calmed already through King Louie, though buses would still access the Civic Center via 14th.

Matt Fernandez said...

That was quite a read, but quite an interesting read.