On Traffic

Traffic at the Jamieson and Fyler intersection is a frequent topic when discussing the Circle K liquor license and expansion proposal. Lindenwood Park residents endorsing the Circle K expansion have made statements to the effect that since there is already a station there, allowing Circle K to expand and sell liquor will not have a dramatic impact on traffic.

I started looking for data sources and came across this CEDS article providing some numbers to work with.

 “As a rough rule of thumb, each proposed pump at a gas station generates about 100 to 130 trips per day. By "pump" we mean fueling position. The convenience store will generate 800 to 1,200 trips per day per 1,000 square feet.” -CEDS referencing the Trip Generation Manual, 9th ed. 

The current facility has 10 fueling positions and roughly 1,600 square feet of convenience store. Using CEDS calculations, this is generating between 2,280 to 3,220 trips per day.

Low:
100 trips per pump x 10 pumps;
800 trips per 1000 sqft x 1.6*
Total = 2,280 trips

High:
130 trips per pump x 10 pumps;
1200 trips per 1000 sqft x 1.6*
Total = 3,220 trips

* 1600 sqft divided by 1000 sqft = 1.6 

As proposed in Circle K’s promotional YouTube video and the Proposed Site Plan, the store would increase to 20 fueling positions and roughly to 4,500 square feet of convenience store.

Low:
100 trips per pump x 20 pumps;
800 trips per 1000 sqft x 4.5**
Total = 5,600 trips

High:
130 trips per pump x 20 pumps;
1200 trips per 1000 sqft x 4.5**
Total = 8,000 trips

** 4500 sqft divided by 1000 sqft = 4.5 

With these calculations, the proposed site can be expected to generate between 5,600 to 8,000 trips per day.

That is 2,380 to 5,720 ADDITIONAL trips every day. And this calculation doesn’t include the draw selling liquor will have to the site. 

All those extra trips will certainly generate more traffic, more congestion, and more accidents at the intersection. The community can likewise expect more trash, more air pollution, and more noise pollution.

If traffic is the only talking point, then it is obvious that the intersection's problems need to be addressed before considering a proposal that will significantly exacerbate the problem.
 
Thanks for reading,
Seth

REFERENCES 

1. Traffic Impacts; Convenience Stores & Gas Stations (Community & Environmental Defense Services)
2. Trip Generation Manual, 9th ed.
3. New Circle K Image, Zach Grogan (YouTube)
4. PDA-011-16-REZ, Rezoning Petition PDF (City of St. Louis)