OTS Rankings Explanation
The Office of Traffic Safety (OTS) rankings facilitate funding decisions and identify emerging traffic safety problem areas. The rankings allow cities to compare themselves to other cities with similar-sized populations and help them identify their potential disproportionate traffic safety problem(s). They also allow counties to compare themselves with all the other counties in the state.
Please note that OTS rankings are only indicators of potential problems; there are many factors that may either understate or overstate a city/county ranking.
Victim and collision data for the rankings is taken from the latest published California Highway Patrol (CHP) Statewide Integrated Traffic Records System (SWITRS) report. OTS provides two types of rankings: victim and collision rankings and DUI arrest rankings.
Victim and collision rankings are based on rates of victims killed and injured or fatal and injury collisions per “1,000 daily-vehicle-miles-of-travel" (2011 CALTRANS) and per “1,000 average population" (2011-2012 Department of Finance) figures. Pedestrian, bicyclist and motorcycle victim rankings do not take into account the size or demographics of a city or county's pedestrian/bicyclist/motorcyclist population.
DUI Arrest rankings are calculated for cities only and are based on rates of non-CHP DUI arrests (2011 Department of Justice) per estimated average number of licensed drivers.
Counties are assigned statewide rankings, while cities are assigned population group rankings. Population groups using 2011 SWITRS data are as follows:
||Collisions and Victims
|A = over 250,000||13 cities ranked||13 cities ranked|
|B = 100,001 to 250,000||55 cities ranked||55 cities ranked|
|C = 50,001 to 100,000||102 cities ranked||102 cities ranked|
|D = 25,001 to 50,000||94 cities ranked||93 cities ranked|
For victim and collision rankings, a Population Group Ranking of "1/102" would be assigned to the city with the highest number of victims/collisions per 1,000 residents in population group C, while a ranking of "102/102" would be assigned to the city with the lowest number of victims/collisions per 1,000 residents in population group C.
For DUI arrest rankings, a population group rank of 1/55 would be assigned to the city with the lowest DUI arrest rate in population group B, while a population group rank of 55/55 would be assigned to the city with the highest DUI arrest rate in population group B.
- Example: Anytown
- Population 75,000 (Group C)
- Victims Killed and Injured in Alcohol Involved Collisions
- Population group ranking 9/102
- The city of Anytown ranked 9 of 103 cities for victims killed and injured in alcohol involved collisions within their population group (50,001 to 100,000). This means Anytown has the 9th highest rate of victims killed and injured in alcohol involved collisions in population category "C".
Cities reporting 0 victims and/or collisions for a category or 0 DUI arrests are ranked using the variable upon which the ranking is based. For example, if 10 of 94 cities in population group D reported 0 hit-and-run fatal and injury collisions when ranking by per “1,000 average population,” the city with the highest population of these 10 cities would be ranked 94/94, and the city with the lowest population of these 10 cities would be ranked 85/94. The same methodology has been applied when ranking per “1,000 daily-vehicle-miles-of-travel” and per “estimated average number of licensed drivers.”
The percentage displayed next to the DUI arrest ranking is the percentage of estimated licensed drivers in each city arrested for DUI. In 2003, 0.8% of all licensed drivers statewide were arrested for DUI. This percentage is used as a measure of DUI enforcement activity in each area; the higher the percentage, the higher the DUI enforcement activity in the area.
OTS recommends that cities use this measure to determine how to adjust their DUI enforcement activity. When DUI enforcement is combined with education and public information campaigns, it leads to a reduction of the incidence of DUI. Cities should therefore increase their DUI enforcement/education/public information activities to meet or exceed the statewide percentage in an effort to decrease the incidence of DUI in their area.