People prefer to cross Clark Street at Menomenee Street in groups of unacquainted individuals.
This is a more detailed post of the one at Streetsblog Chicago.
On the overcast morning of Friday, May 4, 2012, I recorded the speeds of 412 cars at four locations along Clark Street in Old Town and Lincoln Park for 15 minutes at each location. I missed counting the speeds of 42 cars. The embedded map shows the locations and some basic statistics.
What did I find? There’s a relationship between street width and the speed people drive. The highest speeds were found on the widest portions, and the lowest speeds on the narrowest portions. However, this basic study is far from scientific. A better study would record the locations simultaneously (necessitating 4 radar guns), calibrated equipment, consistent training for the researchers on data collection methods, a longer recording duration, and comparison to a control street that had a uniform width at four locations.
View Radar gun places on Clark Street in a larger map
1. Southbound Clark Street at Germania Place
My assistant and I set up the radar gun and camera immediately south of Sandburg Terrace and pointed the radar gun at people driving southbound on Clark Street between a row of parked cars at the concrete median (pedestrian refuge island). Classes would start soon at the Latin School on the east side of Clark Street. Compliance with state law requiring drivers to stop for pedestrians in the crosswalk was weak, to say the least, but compliance wasn’t explicitly measured.
- Average speed: 17.21 miles per hour (MPH)
- Maximum speed: 30 MPH
- Cars measured: 151
- Speed limit: 30 MPH
- Drivers exceeding the speed limit: 0
- Width: 224 inches (from west curb to pedestrian refuge island)
- Effective width: 140 inches (excludes parking by subtracting 7 feet)
- Crashes: 35, of which 4 were bicycle, and 3 were pedestrian.
Only one car-car crash (actually a 3 car crash) produced an injury. What’s interesting about this location is that in a lot of the crashes, the cars were traveling in the same direction. There’s a lot of school drop off and pick up activity here for Latin School of Chicago students, so it could be that many people are pulling away from the curb to merge into traffic and collide.
2. Northbound Clark Street at Menomenee Street
- Average speed: 30.83 miles per hour (MPH)
- Maximum speed: 50 MPH
- Cars measured: 121
- Speed limit: 30 MPH
- Drivers exceeding the speed limit: 53.72%
- Width: 395 inches (from east curb to dividing line). This includes the parking lane but no cars were parked within 50 feet, north and south, of the measurement location.
- Crashes: 20, of which 2 were bicycle, and 1 were pedestrian. Many of the non-bike and non-ped crashes involved a parked car or taxi. The only injuries experienced were by the 2 cyclists and 1 pedestrian.
3. Northbound Clark Street at Lincoln Park West
We stood on the “pie” (traffic island) that separates northbound Clark Street traffic from northbound Lincoln Park West traffic to measure the traffic driving on Clark Street between the pie and the concrete median separating it from southbound Clark Street.
- Average speed: 25.60 miles per hour (MPH)
- Maximum speed: 40 MPH
- Cars measured: 58
- Speed limit: 30 MPH
- Drivers exceeding the speed limit: 27.59%
- Width: 252 inches (from concrete median curb to west curb on the pie)
- Crashes: 4, of which 1 was bicycle, and 2 were pedestrian.
4. Northbound Clark Street between Lincoln Park West and Dickens Avenue
This location is 125 feet north of the previous location.
- Average speed: 22.54 miles per hour (MPH)
- Maximum speed: 35 MPH
- Cars measured: 58
- Speed limit: 30 MPH
- Drivers exceeding the speed limit: 2.44%
- Width: 264 inches (from east curb to dividing line).
- Effective width: 180 inches (excludes parking by subtracting 7 feet)
- Crashes: 0
Me measuring speeding drivers on Clark Street with the speed gun, my clipboard and paper, and a GoPro camera to record the speeding drivers and the results on the speed gun.
Bike Walk Lincoln Park’s proposal
In 2011, Michelle Stenzel and Michael of Bike Walk Lincoln Park published a document to “Make Clark a Liveable Street“. The first two pages show an aerial photo of the same section of Clark Street where I measured automobile speeds, North Avenue and Armitage Avenue. On the first page, existing conditions are laid out. The second graphic shows proposed improvements.
At Menomonee Street, measurement location 2, the document says “pedestrians must cross 6 lanes with no safe haven”, a width of just under 66 feet. In the later pages, the first existing condition is blatant: “Wide lanes of auto traffic moving at speeds in excess of the speed limit”. My analysis in May demonstrates this.
How does BikeWalk Lincoln Park propose to “transform this stretch from a car-oriented ‘super-highway’ to a people-oriented liveable street”? By installing protected bike lanes, putting the street on a diet, and installing new and well-marked crosswalks among other ideas.
Width and speed summary
Ordered by location:
- 224/140 inches. 0% of drivers exceeded 30 MPH speed limit
- 395/395 inches. 53.72% of drivers exceeded 30 MPH speed limit
- 252/252 inches. 27.59% of drivers exceeded 30 MPH speed limit
- 264/180 inches. 2.44% of drivers exceeded 30 MPH speed limit
Ordered from narrowest to widest to see how width relates to speed:
- 224/140 inches. 0% of drivers exceeded 30 MPH speed limit
- 264/180 inches. 2.44% of drivers exceeded 30 MPH speed limit
- 252/252 inches. 27.59% of drivers exceeded 30 MPH speed limit
- 395/395 inches. 53.72% of drivers exceeded 30 MPH speed limit
Notes
Crash data is within 100 feet to avoid the overlap of the final two locations, which were 125 feet apart. Crash data comes from the Illinois Department of Transportation for 2005-2010. The Bushnell Velocity Speed Gun was borrowed for this analysis. The radar gun was filmed to show a speeding car and its speed simultaneously. The video below shows a driver traveling at 50 MPH in a Children’s Safety Zone (as it’s within 1/8 mile of a park, Lincoln Park, making it eligible for automated speed enforcement).
Curiously, no traffic counts have been collected on Clark Street near any of the count locations.
View the video on Vimeo.
Screenshot of traffic count website. Go to the Traffic Count Database System and search for “1700 N Clark Street, Chicago, IL” in the map.
