The I-35W Bridge Detour

MN-DOT was handed a tall order on August 1, 2007. That was to prepare a safe marked detour for 140,000 cars a day with zero prior notice, and hopefully not paralyze traffic in the largest city in the state in the process. Fortunately, we had the nearly forgotten MN-280 4-lane highway and available capacity on the recently rebuilt section of I-94 in our collective back pocket. The detour markings started as a huge number of temporary devices (such as cones), and evolved over time to a smaller set of more permanent markers. This photo tour, shot in early September, 2008, shows the final version of the detour markings. While Flatiron is getting recognized for finishing the new bridge months early, the detour is where MN-DOT really hit a home run. Traffic was relatively smooth despite the unexpected loss of the third most traveled bridge in the state in the heart of the biggest downtown in the state.

This photo tour shows a typical trip through the I-35W detour heading southbound following highways MN-280 southbound and I-94 westbound. Note that some of the photos were shot looking into the sun, so they may lack a bit of contrast.

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The photo above is our starting point at the very north end of MN-280, heading south past the Pacal Business Center and County Road B. The Pacal Business Center was once a major scrap steel recycler. The plant is still used as a steel rolling mill and fabrication plant, but space in the facility is also rented to other heavy industrial businesses. County Road B is open to the right to allow traffic into the Pacal complex. There is also a single lane road along the building made up of a long line of K-blocks. This road allows materials to be moved around the Pacal complex. We can also see a line of K-blocks in the center of MN-280. This is to block any attempt of traffic to use the former County Road B intersection for left turns or a U-turn.

The photo below is a view looking down Walnut Street. Walnut street is blocked with K-blocks at the MN-280 end, and with wooden barricades at Ryan Avenue. This view also shows the divider between traffic lanes. The north half of MN-280 is not built to current freeway standards. In this area, the road is essentially a 4-lane highway with a metal guardrail down the center of the highway. MN-DOT does plan to convert this road into a full freeway at some point in the future.

The photo above is southbound on MN-280 near the Broadway Drive intersection. This is a T-intersection. It is blocked off. The orange sign suggests that traffic use Hennepin Avenue.

The photo below is just north of the Hennepin Avenue and Larpenteur Avenue interchange. The sign suggests that traffic headed to Broadway Drive use this exit ramp.

The photo above is the Hennepin Avenue and Larpenteur Avenue exit. The dividing line between Minneapolis and St. Paul is just to the right of this photo. Many streets change names when crossing the city limits. Hennepin and Larpenteur is one example, Energy Park Drive and Kasota Avenue is another example. University Avenue and Como Avenue are counter examples that keep their names as they cross the city limits.

This interchange had very little in the form of acceleration and deceleration lanes. The ramps are short and have tight curves with limited visibility. The inside loops were dangerously tight, and the narrow bridge piers left merging cars in a dangerous situation. For the detour, MN-DOT did what they could to add to the acceleration lanes. They also removed the inside loops. This interchange will be fully rebuilt in 2009 to bring it up to modern freeway standards.

The big orange sign in the photo below informs motorists that the detour is being handed off to I-94 westbound, and that traffic should stay in the right line for that change. This location is the south end of the Como Avenue overpass.

The photo above is a view of MN-280 as we head southbound. We are in a section where the two roadways are divided by a median. This location is north of the Energy Park Drive and Kasota Avenue overpass. The variable message sign indicates 6 minutes to I-35W, which means that there is no traffic backups at the moment. Notice that MN-DOT installed a line of K-blocks at the left edge of the roadway. This is to provide a center divider wall to keep vehicles from crossing into on-coming traffic in the event of an accident.

The photo below shows MN-280 where the ramp from Energy Park Drive and Kasota Avenue enters MN-280. At this point, the lanes of MN-280 are adjacent to each other divided only by a tall concrete wall.

These two photos are views from near the south end of MN-280. In the photo above, signs indicate that the lanes will split just ahead, with one lane going east on I-94, the other lane going west on I-94. We also have an exit ramp to our right for University Avenue.

The photo below shows that the northbound and southbound have split, but the two southbound lanes are still next to each other.

In the photo above, the lane from southbound MN-280 to westbound I-94 has split from the lane leading to eastbound I-94. In the photo below, we have crossed under I-94, and we are making a long sweeping turn to the right to meet I-94, where it will enter the highway from the left.

In these two photos, we are now heading westbound on I-94. In the photo above, we have entered busy I-94 from a left entrance. To make this left entrance safer, MN-DOT blocked the left lane before the interchange. Prior to the detour, cars entering from the left had to merge into high-speed traffic.

These two photos show this section of I-94 repainted for 4 through lanes. This can lead to some close clearances. For example, in the photo below, the railroad bridge pier and abutment are located directly at the edge of a highway lane, leaving no shoulder and no wide loads.

In these two photos, we continue westbound on I-94. The photo above is a view from the Dartmouth Bridge over the Mississippi River. Note that the big green sign with instructions on how to reach I-35W have been covered up. In addition, a temporary arrow was added to the Riverside Ave exit sign since the exit lane moved a bit to the right when the highway was repainted for 4 through lanes.

The photo below informs traffic that the ramp to I-35W is 1 mile ahead, and that it is an exit only. That means that this lane will split off as part of that exit.

These two photos show that we are getting closer to the I-35W exit. In the photo above, we are three-fourths of a mile from the exit, while in the photo below, we are only a quarter mile from the exit. In fact, if you look up the freeway, you can see the next big orange sign for the exit. It is at the bottom of the small grade.

The photo above is a view of the exit ramp from I-94 westbound to I-35W southbound. Prior to the detour, this exit was optional, as marked by a big green sign. The big greens sign has been covered by a big orange sign since this is now an exit only after the highway was repainted for 4 through lanes. I-94 drops to 3 through lanes after this exit.

We are now in the commons area south of downtown Minneapolis where I-35W and I-94 intermingle. The arrows have been removed from the overhead sign. The reason is that for part of the detour, this section of road was lined with cones and barrels with the entrance ramp getting its own lane, and traffic from the construction zone getting its own lane.

The photo above is the famous hairpin curve on I-35W. The roadway has just been repaved, cleaned up, and new guardrails installed. This area normally is debris strewn and the guardrails are normally mangled as driver misjudge the turn and strike the concrete divider.

The photo below is the famous section of I-35W where you have oncoming lanes of traffic on both sides of your two lanes of traffic. This is very disorienting the first time you drive through this section since it feels like you are on the wrong side of the freeway. What happens here is I-35W splits heading into downtown, and half of the lanes in each direction cross over to the other side of the freeway to end up with two parallel freeways. One freeway enters downtown, the other makes the hairpin turn and heads north towards the bridge over the Mississippi River.