Traffic Operations and Safety

Transportation Data Collection 

The Office of Transportation regularly collects data to make informed and educated roadway safety and operations decisions. The office’s annual Traffic Safety and Operations Report provides data on traffic speeds, volumes and accidents as well as updates on recently completed and ongoing traffic safety and operations projects citywide. The Office of Transportation also collects targeted traffic speed and volume data when required for certain projects, for traffic calming-related requests, or when requested by individual citizens.

2016 Traffic Count Data(PDF, 340KB) 

Traffic Calming Program 

The Office of Transportation regularly receives concerns regarding speeding and cut-through traffic on residential neighborhood streets. These are addressed through a combination of education, enforcement, and engineering measures, collectively referred to as the Neighborhood Traffic Calming Program (NTCP)(PDF, 54MB). The NTCP outlines procedures and guidelines to implement traffic calming measures on residential local and collector streets. The inventory of the traffic control measures considered for traffic calming programs includes:

1. Warning, Specialty, and Speed Limit Signs 
2. Gateways 
3. Textured Crosswalks
4. Special Striping, Narrow Lanes
5. On-Street Parking
6. Bulbouts, Chokers, Curb Extensions
7. Median Island Slow Points
8. Raised Intersections
9. Traffic Circles
10. Serpentine Streets, Chicanes
11. Speed Tables, Speed Humps, and Raised Crosswalks
12. Slow Streets
13. Turn Prohibition Signs
14. Diagonal Diverters, Forced Turn Channelization, Median Barriers
15. One-Way Street Closures, Full Street Closures

More information about these measures can be found in Appendix 1 of the NTCP (page 26 - 67).

Residents may submit a Neighborhood Petition Request for Traffic Calming. After receiving the request, staff will conduct the initial study to determine if the request meets the minimum qualifying criteria as established in the NTCP. The request will be ranked through prioritization criteria for funding the proposed improvements.

The process requires the proposed/requested location to meet certain minimum criteria (traffic volume, speed, etc) in order to be considered for any traffic calming measures. The neighborhood boundaries are then established as the project moves forward to engage/gain support in processing and gaining approval from the residents of the traffic calming elements in accordance with the NTCP.  

Setting Speed Limits

The Office of Transportation conducts Engineering and Traffic surveys to justify posted speed limits so police can use radar for speed enforcement purposes. These surveys take into account prevailing speeds, collision history, roadside conditions not readily apparent to the driver, residential density and pedestrian and bicycle safety. Generally, speed limits are set at the 5-mile-per-hour increment below the 85th percentile speed as determined by a radar survey.

Palo Alto Street Types

The following types of streets can be found in and around our city. 

• Local: Minor roadway that provides access to adjacent properties only.
• Collector: Roadway that collects and distributes local traffic to and from arterial streets, and provides access to adjacent properties.
• Arterial: Major roadway mainly serving through traffic; takes traffic to and from expressways and freeways; provides access to adjacent properties.
• Residential Arterial: Major roadway mainly serving through traffic; takes traffic to and from expressways and freeways; provides access to adjacent (primarily residential) properties.
• Expressway: Major roadway with limited access to adjacent properties; devoted almost exclusively to traffic movement, mainly serving through traffic.
• Freeway: Major roadway with controlled access; devoted exclusively to traffic movement, mainly of a through or regional nature.

Roadway Classification Map(PDF, 533KB)

Road Signage and Striping

Signs and striping are generally used to convey certain regulations, warning and guidance that could not otherwise be made clearly understandable. Signs are classified into four general categories.

• Regulatory signs give notice of traffic laws or regulations
• Warning signs call attention to conditions on, or adjacent to, a highway or street that are potentially hazardous to traffic operations
• Guide signs show route designations, destinations, directions, distances, etc.
• Construction signs provide notice or direction within a construction zone

Traffic Control During Construction

The Office of Transportation is responsible for reviewing traffic control plans that are used for roadway construction work performed by private contractors. Proper traffic control is required in construction areas to reduce accidents, confusion to motorists and damage to private and public property including minimizing impacts to traffic flow.

In order to minimize inconvenience to roadway users, lane closures on arterial streets within Palo Alto are generally limited to the off-peak hours between 9 a.m. and 4 p.m. Sidewalk closures are discouraged, unless there is a convenient and safe alternate path for pedestrians. Work at night is generally not allowed, due to construction noise impacts on nearby residents and hotels.

Traffic Control Plan Submission Guidelines(PDF, 8MB)

Traffic Control Plan Typicals(PDF, 271KB).

Want to learn more?

View our 2017 Traffic Safety and Operations Report(PDF, 12MB)