Tower Grove Ave: What’s Next?

The concrete construction barriers on Tower Grove Avenue which sparked the SafeTGA project are gone.  Yet real hazards for cyclists remain, and upcoming streets projects threaten the very character of this route.  Here are some thoughts about current problems and future concerns, as well as a few ideas about what might help.

Tower Grove Avenue from Magnolia to Shaw is a tree-lined, half-mile stretch of two-lane road bordering the Missouri Botanical Gardens.  With light traffic, sporadic parking, and no intersections, this section is in many ways the heart of this bicycle corridor.  With concrete construction barriers blocking one of its lanes now removed, it is time to ask: what is next for this busiest bike route in St. Louis?

SectionA Lanes

Tower Grove Avenue, Magnolia to Shaw.  The road is 50′ wide on this 0.5 mi segment, and cars travel mostly in the left lane.  The wider right lane is used for parking, cycling, and occasional car travel. With cars parked, safest cycling is out of the door zone, as shown. Occasional Botanical Gardens events increase traffic and parking demands significantly.

Hazards Caption

Cyclist Hazards. Pull-in diagonal parking places cyclists in blind spot as drivers pull out (above left). In heavy traffic cars sometimes drive in right lane (above right).  This intimidates many riders into riding further right than is safe, and greatly exacerbates hazards near parked cars.

On most days, with light traffic and parked cars, the right lane of Tower Grove Ave is a de facto bike lane — automobiles stay in the left lane and bicycles take the right, away from the dangerous door zone of parked cars (see first illustration above).  In heavy traffic, drivers will more frequently drive in the right lane, particularly when few cars are parked.  Right lane travel can be very intimidating to cyclists and is particularly hazardous near parked cars (see second illustration above).  Additional concerns arise on major Botanical Garden events, where the right southbound lane is used for pull-in diagonal parking.  Drivers have limited vision pulling out of such spots; this, together with heavy pedestrian traffic, makes for hazardous cycling on certain days, typically summer weekends.

The biggest threat to Tower Grove Ave as a safe cycling corridor is the upcoming closure of Kingsighway Boulevard for two years starting Spring 2014 (Kingsighway is an arterial paralleling Tower Grove Avenue a half mile to the east).  Although Tower Grove Avenue is not a designated detour, there is little doubt traffic will increase.  Heavier car traffic poses a real threat to the character of this road and its viability as a core bicycle corridor: besides intimidating riders into more dangerous positions, it will increase cyclist conflicts at the Shaw and Magnolia intersections.

What can be done to make Tower Grove Avenue a safer street to ride, both during the Kingsighway closure and after? Below are some options.

  • Sharrows The “minimalist” approach is to maintain the status quo, with right lane sharrows emphasizing that the lane is to be shared between cars and bicycles.
  • Bike Lane A dedicated bicycle lane would show in paint the safest path for cyclists to travel.  The road width can comfortably accommodate a travel lane, standard  bike lane, and parallel parking, and such a treatment would make right hand travel illegal (but would not prevent it entirely).  Worryingly, cars would intrude into a bike lane during Botanical Garden event diagonal parking.
  • Green Lane A dedicated bicycle lane would be painted green, increasing its prominence and discouraging illegal right lane car travel. Variations such combined green lane and sharrow treatments exist, but are not in common use.
  • Separated Bike Lane Dedicated bicycle lanes could be further isolated from traffic by physical barriers such as plastic “bollards”, or by placing parking to the left of the bicycle lane.
  • Curb Bulb-outs Strategically placed curb bulb-outs, like those on nearby Grand Avenue, would calm traffic and altogether eliminate right lane car travel while providing pedestrian-friendly street crossings.
  • No diagonal parking Abandoning angled parking would significantly increase cyclist safety at the cost of roughly 50 on-street parking spots.
  • Back-in parking If angled parking must be maintained, back-in parking is the preferred treatment, being safer for cyclists and pedestrians.

What should a safe and accessible Tower Grove Avenue look like?  And what can be done quickly, so it remains safe with Kingshighway closed?  Share your thoughts below, or on our Facebook page.


There is a wide variety of information available about bicycle infrastructure, both from an advocacy and design point of view.  In addition to links above, here are a few particularly useful design references:

Posted in Advocacy and Opinion, Tower Grove Ave
3 comments on “Tower Grove Ave: What’s Next?
  1. Herbie says:

    Ever played with the Streetmix app?

  2. Linsey Kornya says:

    With few curb cuts, this stretch of TGA seems like a great opportunity for STL to try out its first cycle track/dedicated bike lane with parking to the left of cyclists. Perhaps more people would bike to the gardens on busy days if there was pathway that felt safer to less experienced cyclists, possibly decreasing the parking crunch for the garden. We are often shocked when, after navigating truly insane traffic and parking conditions during festival days, we discover virtually empty bike racks. I hear from friends in TGS who drive to the garden that they don’t perceive a safe or legal way to bike there (especially since the roads to shaw are all blocked and/or have bike unfriendly speed bumps).

  3. admin says:

    Linsay — separated cycle tracks or parking to left of cyclists are an idea worth considering, and Tower Grove Ave is wide enough to accommodate them *if* there is no angled parking.

    One concern I have, though, regards maintenance: what happens when slippery wet leaves litter the ground and the City has not swept them? In such situations, it is a real advantage to be able to leave the bike lane and travel in the car lane. With left parking especially, this would be very difficult.

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