Traffic Calming Data

Collecting vehicle volume and speed data is an integral part of our Traffic Calming Program. We collect this data using radar during the application process for traffic calming on a proposed street. If a street is selected and traffic calming measures are installed, after data is collected to determine how well the measure has performed. Please see our webpage for more information about the Neighborhood Traffic Calming Program.

If you have any questions about the Traffic Calming Program please email us at trafficcalming@pittsburghpa.gov

*Changes in average daily trips may be impacted by factors such as weather and holidays.

Glossary:

Street Name: This is the location of the new traffic calming measure

Project Type: This is the type of traffic calming measure that was installed, typically speed humps or a larger road diet.

• Speed Humps: These are raised surfaces on a roadway typically installed at intervals to reduce excessive motorist speeds. They are typically 3-4 inches in height, have approach and exit ramp lengths of 2-6 feet, and may extend along a majority of the width of the roadway. Dimensions vary depending on the amount of speed reduction needed to obtain a median speed equal to the legal speed limit, or posted advisory speed limit.
• Road Diet: This is a lane restriping project that reduces travel lane widths and/or changes lane uses. Alternate cross-sections may include the addition of dedicated left-turn lanes, on-street parking, bicycle facilities, raised medians, or sidewalks. A common application converts a four-lane, two-way roadway to a three-lane roadway – one through-lane in each direction with designated left turn lanes. The goals of a road diet project may include reducing excessive motorist speeds, maintaining the existing vehicle capacity of the street, increasing the efficiency of other modes, and increasing safety for all users.

Median Speed (MPH): This is the middle number from the recorded speeds and is different from an average because it is not weighted by the total number of vehicle trips and does not represent the most common speed.

The three numbers are the median speed before traffic calming measures were installed, after they were installed, and the difference between these two speeds.

All speeds are measured in miles per hour.

85th Percentile Speed (MPH): This is the speed that the majority (85%) of drivers traveled at or less than, this means 15% of drivers traveled faster than this speed.

The three numbers are the 85th percentile speed before traffic calming measures were installed, after they were installed, and the difference between these two speeds.

All speeds are measured in miles per hour.

% of Drivers Speeding: This is the percentage of the total number of vehicle trips traveling over the posted speed limit.

The two numbers are the percentage of drivers speeding before traffic calming measures were installed, and after they were installed.

Average Daily Trips (ADT): This is the average of the vehicle trips recorded each day, this is not the number of unique vehicles or drivers and this counts vehicles traveling in both directions.

Location: This is the Council District(s) and Neighborhood(s) where the street is located.