Tag: traffic calming

photo of Hadiya Pendleton Park, seen from the 43rd Green Line station platform.

Traffic calming around Chicago schools and parks

July 26, 2023 / / 0 Comments

Reducing the number and speed of automobiles near schools and parks is a proven way to reduce the number of traffic crashes involving children, part of a practice known as “traffic calming”. In Chicago a key way to do that has been to “cul-de-sac” (which I’m using as a verb) a street to prevent through traffic (reducing the number) and preventing speeding (reducing the speed).

My study of this was inspired by the above tweet, where the person is accurate when they say, “it works with any street”. Indeed: Full access to the school or park and to every property on the block is maintained, but drivers are not able to go through while pedestrians and bicyclists can (another practice called “modal filtering“).

My favorite example in Chicago is Hadiya Pendleton Park, at 4345 S Calumet Ave. This project created two mid-block cul-de-sacs and a park in the middle of a block, using vacant city-owned land on both sides. Creating new open space is a common corresponding outcome of the cul-de-sac application, which is what occurred at Funston Elementary School (see the before and after aerial photos below).

two black and white aerial photos taken of Funston Elementary School, one in 1998 showing a 4-way intersection of McLean Ave and Central Park Ave and one in 2003 showing a cul-de-sac on McLean Ave west of the school and landscaped area between the cul-de-sac and the three-way intersection of McLean and Central Park.

Through Twitter I solicited additional examples of where the city has created traffic calming near schools and parks using cul-de-sacs. Examples were submitted by Roland, Emily (who mentioned Funston), Matt, Steven, and another tweeter.

Using OpenStreetMap, Overpass Query Language, and Overpass Turbo, we can find all of the schools and parks that are within a specified distance of a cul-de-sac. It turns out there are 153 schools and parks in Chicago that are within 150 feet of a cul-de-sac. (This considers only schools, parks, and cul-de-sacs, tagged as “turning circles”, currently mapped in OSM, and I have not verified each of the 153 instances.)

Map showing parks, schools, and adjacent cul-de-sacs, the results of the Overpass Turbo query.
Map showing parks, schools, and adjacent cul-de-sacs, the results of the Overpass Turbo query. An inset map shows a zoomed in portion of the map to illustrate the different types of features captured in the Overpass Turbo query (specifically it shows Graham Elementary School and McInerney Park).

The query below will find all of the cul-de-sacs (mapped as “turning circles” in OSM parlance) that are in Chicago, all of the schools and parks in Chicago, and then all of the two categories of features that are within 45 meters of each other. (Run the query and show the map, which will always grab the latest data.)

/*
example from OSM wiki: https://wiki.openstreetmap.org/wiki/Overpass_API/Overpass_API_by_Example
*/
[out:json][timeout:25];
// fetch area “Chicago” to search in
{{geocodeArea:Chicago}}->.searchArea;

// get cul-de-sacs
(
  node["highway"="turning_circle"](area.searchArea);
)->.turning_circles;

// get parks and schools
(
  way["amenity"="school"](area.searchArea);
  way["leisure"="park"](area.searchArea);
)->.schoolsParks;

// find parks and schools near cul-de-sacs
(
  way.schoolsParks(around.turning_circles:45);
)->.matchingSchoolsParks;

// find cul-de-sacs near parks and schools
(
  node.turning_circles(around.schoolsParks:45);
)->.matchingTurningCircles;

// output results to the map
(.matchingSchoolsParks; .matchingTurningCircles;);
out geom;

Read the three other blog posts I’ve written about using Overpass Turbo to quickly sift through and extract desired mapping data from OpenStreetMap.

Comment about traffic calming

August 5, 2011 / / 0 Comments

“Speed bumps are never the answer when chicanes and choking a street to one lane briefly with curb extensions get the same job done more safely. There’s literally no application where speed bumps are more appropriate than a chicane or chokers in any location they’ve been used by PBOT [Portland Bureau of Transportation] so far.”

From Paul Johnson on BikePortland.org.

Photo of drivers straddling the streetcar tracks and impeding the bike lane, in Lovejoy Street in Portland, Oregon. 

The blizzard’s calming effect

February 7, 2011 / / 0 Comments

Last Wednesday night, after the blizzard had stopped and the city had plowed arterial roads, I took two buses to Pilsen in 36 minutes. Transit buses have an average speed lower than bicycling and I don’t think I could have biked there in 36 minutes. (I didn’t want to bike because I didn’t know the condition of roads from my new place in Avondale to dinner in Pilsen.)

I credit the speedy journey to the complete lack of cars on the road and the few people wanting to go out on Wednesday, as well as ride the bus.

The blizzard gave Chicagoans a break. Hundreds of thousands of workers stayed home on Wednesday. Thousands more got the day off on Thursday. Car traffic remained light through Friday and the Chicago Transit Authority trains and buses were packed on Thursday (partially because of mechanical problems on the Blue Line but also because of new riders who couldn’t drive or carpool).

Chicagoans enjoy strolling through Humboldt Park. Photo by Joshua Koonce.

Many people took walking tours around their parks and neighborhoods, or went to see the calamity of Lake Shore Drive. Flickr is loaded with the explorers’ photos. Check out 2,000+ labeled “snomg chicago.”

The blizzard’s effect on traffic and roads

The snow plows inadvertently created a curb extension at the main intersection in Wicker Park, often used as part of a traffic calming project. This was gone on Saturday, but in addition to its removal, the entire corner sidewalk was cleared.

A lot of bike lanes are buried right now and people riding bikes are riding in the middle shared lanes, further calming traffic. I’m not sure how long the civility I noticed between drivers and bicyclists last week will last, even as bike lanes remain “closed” or have been illegally co-opted into backup parking lanes. See next photo.

These drivers have illegally parked their cars in the bike lane. The municipal code does not offer any relevant (i.e. snow-related) exemptions for parking or standing in bike lanes.

Riding and driving through town has been interesting. There’s no room for people riding bikes to share the lane with drivers side by side, so they must share it front to back.

Humboldt Park “do over”

January 27, 2011 / / 0 Comments

Read the story below and the final paragraph to fully understand this drawing.

If you, like Alderman Roberto Maldonado (26th Ward), received complaints about speeding traffic and difficulty crossing Humboldt Drive, how would you respond?

The Chicago Department of Transportation (CDOT) responded by temporarily changing “the four-lane street into two travel lanes with a center lane used as a combination left-turn lane and pedestrian refuge area, using orange traffic barrels to keep moving cars out of the center lane.” (All quotes from Vote With Your Feet / Time Out Chicago, by John Greenfield.)

Narrowing the lane could reduce automobile speed and the refuge island should make it easier to cross the street, even if it has to be done in two movements. “After CDOT analyzes the effects on traffic speed and behavior, [CDOT spokesperson Brian] Steele says, the changes may become permanent next year.”

But bicyclists are not considered in this installation. That seems to be by design.

“He [Alderman Maldonado] told me that he has no intention of adding a bicycle lane or any other accouterments on that stretch because ‘the road is too dangerous for pedestrians,’” she says. Lottes recently posted on the local bike website thechainlink.org, asking members to lobby Maldonado for bike lanes on Humboldt. “To me the road seems too dangerous for pedestrians because there are no sidewalks, crosswalks or bike lanes.”

A local resident, Gin, asked me if I could draw up something for Humboldt Drive and I drew what you saw above. I based it on a bike lane design I saw in New York City: two-way, barrier protected (see photo below). The intersections between the bike lane and the other lanes will need special care – I don’t have any expertise there, but I know some people in Portland and New York City who do.

What else might you propose? Here’s a map of the park (centered on where I drew the bike lane), and a street view of the location.