I-70 at Cass
Interstate 70 looking north from Cass Ave with Mississippi River Bridge construction in the background.

Come 2015, downtown commuters may lose access to the I-70 reversible lanes thanks to a combination of construction for the new Mississippi River Bridge and a landscaped highway “lid” across I-70.

When the new Mississippi River Bridge opens to traffic in 2014, commuters on I-70 will have to deal with one less lane of westbound pavement. That’s because the space currently utilized by the far right lane of westbound I-70 will be taken up by a ramp coming off the new bridge. Thus it’s fair to say that many I-70 commuters who work downtown will make an extra effort to access the highway’s reversible lanes to avoid rush hour congestion. The only problem, downtown commuters might not be able to access them, either.

Commuters leaving downtown once had access to the reversible lanes via an onramp from 9th St. Construction on the new bridge, however, has eliminated the ramp. A slip ramp from the left lane of I-70 just north of the MLK bridge is the only remaining access to the westbound reversible lanes.

Meanwhile, one of the major components of plans to revitalize the Arch grounds is a one-block landscaped lid across I-70 and removal of Memorial Dr between Market and Chestnut. So that the closure of Memorial Dr does not isolate Laclede’s Landing, City-Arch-River has proposed reversing the direction of the I-70 ramps just south of Washington Ave: the eastbound exit ramp becomes an entrance ramp, the westbound entrance ramp becomes an exit ramp. N 3rd St will, also, be extended to connect with the MLK bridge onramp to I-70.

The problem, however, is that the proposed ramp reversal would completely eliminate access to the I-70 reversible lanes for commuters leaving downtown (the onramp just north of the MLK bridge is too close to the reversible lane entrance to provide safe access). Downtown commuters would have to detour to Soulard to safely access the reversible lanes.

So for those keeping count, a one-block closure of Memorial Dr will necessitate rebuilding two ramps to and from I-70 at Washington Ave, the slight widening of the “depressed section” north of Pine, an extension of N 3rd St at the MLK bridge, and a new highway ramp to the reversible lanes. That’s a lot of expensive infrastructure just to remove 300-ft of road.