Intersection Intervention: Union and Lindell

Intersection Intervention: Union and Lindell

Road reconfigurations and pedestrian and bicyclist safety are top of mind in St. Louis between last year’s Board Bill 120, the City’s upcoming Mobility Plan, and debate on how to spend the Rams settlement money. With increasing financial resources and support from residents we should closely look at every reconstruction and repaving project as an opportunity to engage St. Louis residents on how we can make streets safer for all users. The first opportunity in 2024 to do so comes with the replacement of the Union/Lindell bridge over Forest Park Parkway.

In the Fall of 2022, the City of St. Louis posted an online community survey regarding the replacement of the Union/Lindell intersection bridge. This is a monumental opportunity for the City, as the intersection serves as an entrance to Forest Park, a key bike route on Union, and as an interchange with Forest Park Parkway’s on/off ramps. The intersection is also complicated, being a bridge over Forest Park Parkway itself and the Metrolink tracks. All of these factors make this a very complex and expensive project for the City.

Flash forward to late December 2023, the engineering consultant hired to lead this project, HDR, presented their conceptual design to the Forest Park Advisory Board. While the design presented is certainly an improvement over the existing intersection, it’s completely lacking in most regards to pedestrian and bicyclist safety. This was mentioned in the previous article linked above, but I have additional concerns with this proposal and see an opportunity for an alternative design. This is a roughly $27 million project, so it is important that we get the design done right, before construction starts. Changes to the design after construction will be considerably more expensive and limited to the confined space of the new bridge.

First is the multi-use path (MUP) on the west side of Union, being proposed here in lieu of protected bike lanes on the street. A MUP is an inadequate design for this area. The bike lanes that currently exist on Union to the north are some of the only protected bike lanes in the entire City, and the bike path to the south in Forest Park is one of the busiest, if not the busiest, trail in the City for both bike commuters and recreational cycling. Additionally, given the steep elevation change between Grand Drive and Lindell the large number of cyclists, runners, and walkers that use the park’s trails will feel cramped and unsafe on this proposed MUP.

Second is the lack of accommodation within the intersection for cyclists. The proposal shows the MUP coming into the intersection on two sides, in addition to the bike lanes north on Union, and new bike lanes proposed on Lindell. This design will inevitably require some cyclists to make turns in multiple stages, with not so much as even a bit of green paint on the pavement.

Third is the new connector road between Union and Forest Park Parkway. This proposed design does make sense and helps remove the current poorly placed westbound off-ramp (labeled in the above image as “Slip lane removed”). However, this new design requires two new traffic lights to be installed and synced with the main intersection. Traffic lights are quite expensive to install. The Federal Highway Administration reports the average cost to build a new traffic light is over $500,000. That’s roughly $1 million spent to construct this new connector road, and on top of that Forest Park Parkway will also need to be modified to make room for a new left turn lane at the new signalized intersection. All of this cost is being proposed to save a small handful of drivers a couple minutes. A cheaper solution, for those people driving northwest between Kingshighway and Union, would be to use Lindell.

A Better Plan

In the Spring of 2023, following the initial Fall 2022 survey, I felt inspired to create my own design for this intersection. Following the best practice, NACTO design principles, I drew the following image of a completely protected intersection with continuously protected bike lanes on Union, extending them south to Grand Drive. I also assumed, as did HDR in their proposal, that Lindell will get a road diet with some unprotected, painted bike lanes. While this may not be the best design for bike lanes on Lindell, it’s unfortunately the most realistic option at the moment until the City dedicates consistent annual funding to bike infrastructure.

This alternative intersection design has the same dimensions as the original bridge and road widths. However, there’s plenty of room to tweak the design to reduce cost, without compromising on safety. The feasibility for this design comes from the removal of the right turn lanes that currently exist on 3 sides of the intersection (all 3 are slated to remain in HDR’s design). These dedicated right turn lanes function essentially as slip lanes for cars, encouraging drivers to keep moving quickly and discouraging them from looking for pedestrians. Even during red lights, right turn lanes can still pose safety challenges to pedestrians with “Right on Red” being allowed by default in Missouri. The only guaranteed way to prevent drivers from making a right on red, is to stop building dedicated right turn lanes. Repurposing these right turn lanes for the protected intersection therefore improves safety not just for cyclists, but also pedestrians and drivers.

If you are unfamiliar with the “protected intersection” concept, the website – – has a great video explaining how it works. Essentially, the protected intersection extends the protected bike lane design through the intersection, rather than stopping and starting on each side, leaving only paint in the middle. Cyclists can navigate through the intersection in a similar manner to a roundabout, making left turns possible without ever needing to share space with cars. The City also recently, and fairly quietly, completed its first attempt of a protected intersection at Jefferson & Chouteau. Although the design of the Jefferson & Chouteau one has a few issues and leaves many cyclists confused, my proposed design for Union/Lindell is fully protected on all 4 sides.

Digging into the details of this alternative design, the bottom of the image shows that the eastbound on-ramp to the Parkway remains exactly the same as today without a signal. This ramp could be removed with little impact to drivers but I kept it in the design for simplicity. In an effort to simplify the intersection, and maximize safety, the westbound off-ramp has been removed.

As for the intersection itself, the above image explains the major points. The design is fairly standard for a protected intersection and incorporates several traffic calming elements, including bump outs, pedestrian refuge islands, truck aprons, and left turn hardening. All of the turning radii here are large enough to accommodate buses and large trucks, but not larger than necessary to maximize the safety of pedestrians and cyclists. For St. Louis this would be a (almost) first of its kind, but for other US cities like Seattle, Salt Lake City, or Fremont, this is now standard practice.

An example from Milwaukee – WISN – Raised bike lanes, concrete islands installed on Milwaukee street meant to slow down traffic

Opportunity To Act

At the moment, HDR is still working with the City and the other sub-consultants to finalize the design. A public open-house to give feedback on the HDR proposal will take place on January 30th, 2024 from 4pm-7pm at the Forest Park Visitors Center, 5595 Grand Drive. According to the City’s website, final design is expected to be complete in the Winter of 2024. There is still plenty of time for HDR to change the design after collecting feedback on January 30th. I encourage everyone that is able to, please attend this public meeting and demand a better design. The open-house style meeting means that the public is free to show up at any time between 4 and 7pm. Anyone is welcome to stay for as long or little as they want. The consultants and city staff will be there to answer questions, and there will likely also be a way to give written feedback.

The design shown here was not created by a licensed Professional Engineer. Additionally, if another online method of providing feedback becomes available, this article will be updated.


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