Designing streets for people

Streets can be a place for both people and cars; it just requires looking at streets as a people place first.

Placemaking is about creating places for people. This includes streets which make up most of the public spaces in our communities. One of the problems is when streets are designed for cars, not for people. Streets can be designed for both people and cars. When that is done it is a safer environment for both. Streets are a means of moving around in a place and streets need to accommodate all types of users. Michigan State University Extension will show you better tools for moving people from place to place instead of streets (such as roads, highways, and high speed transit).

Conventional street design focuses primarily on mobility of cars. The main system currently in use to classify different types of streets’ functions use classification names which underline the idea that cars come first. Local streets move cars from places such as homes to collector streets. Collectors gather and move cars to arterials which move large volumes of cars to destinations. The classifications are based on how much delay a car faces in its journey.

Speeds on these streets are also not designed for people. The more one goes above 20 miles per hour car pedestrian accidents become increasingly fatal for pedestrians. A report from the American Automobile Association Foundation in 2011 looked at impacts speeds and pedestrian injury. The findings are summarized here.

Speed

23 MPH

31 MPH

39MPH

46 MPH

Severe Injury

25%

50%

75%

90%

Speed

23MPH

32MPH

42 MPH

50 MPH

Fatality

10%

25%

50%

75%

There are several factors communities can undertake to make streets safer such as increasing the distance of separation between cars and pedestrians and including ''physical buffers such as parked cars or street trees. Changing posted speed limits is not as effective or not effective at all, because the physical design of a street has a greater impact on traffic speeds. Design speed for a standard neighborhood street should include all of the techniques to slow traffic and create buffers for pedestrians. The cross section to the right shows a typical neighborhood street with a curb to curb distance of 28 feet. This allows for parking on both sides and a design speed of 20mph through the use of a yield travel lane. Curb radius is tight at 10 feet. If the pavement is narrower than 28 feet parking on one side with two 9 feet travel lanes can be used for the same design speed. The important design factor is to create a space that says cars must drive slowly. Pedestrians are buffered by parked cars and a 6 foot planting strip with trees. This type of street design paired with small setbacks creates an environment that says people and cars are welcome here.

Commercial areas have the same design consideration for pedestrian comfort and safety. Design speeds need to be kept slow, 25 mph or less, and pedestrian space needs to be buffered. Travel lanes are wide enough to accommodate traffic but still narrow enough to control speeds. The pavement width is 34 feet and this provides for parking on both sides and two 10 foot travel lanes. The narrow pavement width is important as it allows pedestrians to easily cross the street, usually in under 10 seconds. There is not a planting buffer but street trees are placed in planter ''boxes on the wide sidewalk. The total width of the right–of-way is 60 feet which, combined with a building height of two stories, provides a sense of comfortable enclosure for pedestrians. This type of design helps create place and also send the message to motorists that is a place for people.

In a commercial area where the right of way is large, in excess of 60 feet, different design tools can be applied to create a pedestrian safe street. One key factor is maintaining only two travel lanes. The surplus right of way is taken up by wide sidewalks and angled parking. Street trees are placed in tree boxes on the sidewalk and spaced appropriately. Curb bump outs may be used to shorten pedestrian crossing. All of this is done to maintain a design speed of 25mph.

All of these examples look at moving vehicles through pedestrian places. They are not examples of how to move vehicles from place to place. There are different street designs for place to place movement. Such streets can be designed to make pedestrians safe and move large volumes of traffic. In the functional classification system these would be considered arterials and focus strictly on mobility of vehicles with a design speed of 35 to 50 mph. Arterials are often made up of several travel lanes and turning lanes. In addition, to maintain traffic speeds curb’s radii is large. These design features makes crossing times at intersections lengthy and unsafe. Because of high speeds setbacks are often large this then leaves any pedestrian space feeling isolated and unprotected.''

 In urbanized areas using design tools such as a median to separate travel lanes. That median also provides a pedestrian refuge when crossing the street. That creates a
safer environment for people. Street trees are used to shape the space and create a slower design speed. Sidewalks are buffered by on street parking and a continuous planter strip. Travel lanes are kept relatively narrow at 10 feet. Curb radii is small at 10 feet. The design speed for this type of street is 25-30 mph.

Which street design, or street standards, to use should be calibrated to the surrounding urban context. (See this article on transects.) Looking at the context of the street in relationship to the surrounding environment and the purpose of the street allows these areas to become a place for people and vehicles to occupy together safely. For more information on street standards and placemaking in your community, contact a Michigan State University Extension Land Use Educator

 

Related Events

Related Articles

Related Resources