Pedestrian Safety Guide and Countermeasure Selection System


Case Study No. 45

Elm Street Traffic Calming

Tucson, Arizona

Prepared by Laurie Actman, Patrick McMahon, Henry Renski, University of North Carolina Highway Safety Research Center, and Vincent Catalano, City of Tucson.


Pedestrian safety and comfort suffer when a neighborhood street designated as a collector was needed to carry significant bicycle, pedestrian, and motor vehicle traffic as a gateway to a major university and medical center as well as an access route for a luxury hotel.


The slight slope and contrasting brick design of the raised crosswalk indicates the designated space for pedestrian crossing to approaching motorists.

As an extension of Pima Street, a heavily traveled collector in the city of Tucson, Elm Street is designated a collector road. Although much of the traffic on Pima Street is diverted before it becomes Elm Street, average daily traffic (ADT) for Elm still totaled 8,000 vehicles when this project was implemented. The street also carried heavy and constant bicycle and pedestrian traffic.

At the far end of Elm Street is an entrance to the University of Arizona’s University Medical Center, a teaching hospital. The street is located in a high-end residential neighborhood also home to the Arizona Inn, one of the City’s more exclusive hotels. The property owners along Elm Street were concerned about speeding traffic on the street and struggled over how to reduce speeds. The posted speed limit was 25 mi/h, and because of the street’s designation as a collector, speed humps were not allowed. After a traffic light was installed at a nearby collector,, travel volumes on Elm increased as even more drivers began using the street as an alternative entrance to the University. Some property owners wanted to close its far end and eliminate the street as a route for through traffic; however, surrounding neighborhoods were concerned that the diverted traffic would merely shift onto their streets. Forced-turn devices were installed, but emergency service vehicles had difficulty getting onto the street.


Tree-lined medians and small chicanes reduce drivers’ perceived speeds on Elm Street.

After 20 years of controversy, the property owners on Elm Street petitioned to initiate the Neighborhood Traffic Management Program for their street. The program allows a majority of residents in a neighborhood to designate a Neighborhood Improvement District and charge a special assessment upon property owners in the district to fund improvements. Upon City approval of the request, a neighborhood traffic program was instituted for Elm Street. The residential Traffic Advisory Committee then hired a local architect to design a traffic mitigation plan.

The Traffic Advisory Committee worked with the property owners, surrounding neighborhood associations, the University of Arizona, the bicycle advisory committee, and the City of Tucson. All agencies and committees approved the final plan. Data was collected in 1990 prior to construction and after construction in 1994. Speed data was also collected from counters set after construction.

Drawing of the approved plan for Elm Street’s traffic calming and beautification.

The design’s goal was to use beautification along with direct engineering measures to reduce the speed of traffic without diverting it into adjacent neighborhoods. The approved plan consisted of several small chicanes on both sides of the street, several tree-lined medians, and a raised crosswalk. Parking is allowed on both sides of the street. The chicanes extend slightly further than the side street parking to provide greater visibility for pedestrians wishing to cross the street and to change drivers’ perceived speed of the street by fracturing its straightness. The medians were added mainly to further fracture the perceived speed of the street rather than to act as pedestrian refuge islands.

Trees were planted along the street and in the chicanes to create a canopy for the street. The tree canopy provides shade for parked cars, pedestrians, and bicyclists while enhancing the appearance of the street and keeping speeds down. The raised crosswalk is slightly sloped and at grade with the sidewalk causing many drivers to slow while approaching the crosswalk. The brick design adds to the streetscape and provides contrast against the pavement, indicating to drivers the designated space for pedestrian crossings. Signs indicate that motorists are required to stop for pedestrians in the crosswalk.


Initially, the traffic volume after construction increased by only a small percentage. However, a 2010 traffic count indicate average daily traffic volumes of approximately 4,000 vehicles per day (5,000 vpd in 2004). After construction, the 85th percentile speed was measured 30 mi/h, which is desirable for this type of street. No before speeds or volumes were recorded, but, anecdotally, speed reductions have been noticeable.

After 20 years of dispute, the Elm Street controversy ended with the construction of a beautiful and effective project. To pay for projects of this nature, which are over and above what the city can provide as routine traffic calming and streetscape enhancement, Tucson established local Improvement Districts (IDs). The $120,000 cost for the project was bonded over ten years, and was funded by the property taxes of local property owners. Because the luxury hotel owns the largest property in this ID, it funded 40 percent of the overall costs.

According to traffic engineering staff who oversaw the implementation of the traffic calming device, pedestrians crossing between a nearby hotel and parking lot are reported to feel safer and more comfortable when using the raised crosswalk. With an improved pedestrian environment, walking continues to be a popular activity in the neighborhood.


Jesse Soto
Traffic Engineering Manager
City of Tucson
201 N. Stone Avenue
Tucson, AZ 85726
Office Phone: (520) 791-4259