May 26, 2008

Taking down freeway spurs, and some possible Minneapolis examples

First off, a quick update, as I've been out to sea for 3 months. The Minnesota Legislature DID pass a transportation funding bill, which was promptly vetoed by the Governor. However, when the veto override vote came up, six House Republicans chose to break ranks and vote for the bill, and so both MnDOT and regional transit finally have their first real surge in funding in years. Afterwards, and somewhat in keeping with requirements in the bill, MnDOT announced accelerated timetables for several bridge replacements, including the US 52 Lafayette Bridge, the US 61 Hastings Bridge, and the MN 23 DeSoto Bridge in St. Cloud...which has been closed for the past month after an inspection brought up concerns about the gusset plates.


Moving on to more recent events, about a week ago was the first of some articles around the country (mainly the same article/story appearing in different locations on different days) on removing freeways from urban areas, especially blighted elevated freeways, and highlighting Oklahoma City's removal of I-40 through downtown.

What some of these articles barely mention, however, is that I-40 is not being eliminated. It's being relocated to a covered-over trench along an old railroad line a few blocks to the south. While this will allow the city to build a park along the existing I-40 right-of-way, to say that the freeway is being torn down to make room for a park, without discussing the relocation, is misleading.

Supporters are quick to point out real-life examples of freeway removal as a talking point for further projects. It should be pointed out that most of these removals were spur routes, not major through routes. They were also done either due to structural damage (i.e. the Embarcadero in San Francisco after the '89 earthquake) or because the route was underutilized (i.e. the Park East in Milwaukee).

That said, the story has opened up discussion nationwide about removing or relocating freeways from undesirable locations, either for aesthetic reasons (i.e. along a waterfront), or to open up areas of the central city for redevelopment. Minneapolis is no exception, and there's been some discussion on the StarTribune Roadguy blog about doing the same thing in Minneapolis. Two of the more popular suggestions involve downgrading the 3rd St spur east of the Metrodome that feeds into the U of M campus, and downgrading the 3rd/4th St spur from 2nd Ave N to I-94.

Removing the spur east of the Metrodome to the "U" has several issues related to it, between it being the primary route into and through campus, the proposed Central LRT line, and elevation/grade differences between Cedar Ave and the spur. I'll save this for a future discussion.

Below are some points on the other freeway spur...along 3rd/4th St between I-94 and 2nd Ave N:

- Average traffic volumes on the spur are about 20K daily. Combined with the existing 3rd St/4th St, it’s a total of about 23K. This is on par with many of the one-way pairs around downtown.

- With that in mind, it’s within the realm of possibility to take down the freeway spur and create a 3rd/4th St “boulevard” in between I-94 and 2nd Ave N.

- To maintain traffic flow, though, two main recommendations, if not outright requirements, would be A) traffic signal progression, and B) three lanes on each street. I don’t remember street widths offhand, but I think it’s possible to maintain 3 traffic lanes and still have enough street width for parking and a bike lane, especially inbound along 4th St (which has the wider width available due to the overpass).

- One of two areas of concern is bridging over the BNSF rail tracks. I don’t remember the elevation difference between the BNSF trench and old 3rd St/4th St, but if there’s enough of an elevation difference, you should be able to bridge over the rail tracks without having to bridge over 5th Ave N as well.

- The other area of concern is connecting to the I-94 ramps, especially outbound on 3rd St. The inbound connection to 4th St shouldn’t be much of a problem, but the outbound connection currently has a large building in the way…this building is what causes the break in 3rd St between 10th Ave N and 12th Ave N. It’s not insurmountable, but it may require some tight curviture and will definately impact the parking lots at the building.

So, in a nutshell, I think one's doable, but the other has too many issues that need to be sorted out first.