5. PROGRAM EVALUATION (continued)5.1.10 Extent of Speed Violation
Although there was no space allocated on the police stop form for recording the speed that prompted the stop6, some officers wrote one or more of the following items of information on the form – posted speed, actual speed or amount the vehicle was moving over the posted speed. In Phoenix , 552 forms (69.5%) contained data that indicated the amount that vehicles were traveling over posted speeds. The data for those 552 forms are shown in Table 21.
Table 21 shows that vehicles stopped in Phoenix for which the police wrote in data exceeded posted speeds by a range of 6 to 31 miles. In 88% of the cases, the vehicles exceeded the posted speeds by 10 mph or more. The roads on which these vehicles were traveling had speed limits of either 25 or 30 mph.
The Phoenix data on extent of speed violation were not obtained from all neighborhoods. No speed data were available for any stops made in the Clarendon neighborhood. This is not surprising since, as will be discussed later, prevailing speeds on Clarendon were quite low because of the speed humps that had been installed prior to the commencement of this study. Even the higher speeds between the humps were not sufficient to prompt the officers to make a note. In terms of the other neighborhoods, 58.7 percent of the speed data came from stops made in the Moon Valley/Coral Gables neighborhood, and 41.3 percent came from stops made in the Sweetwater neighborhood.
Only 38 of the police stop Peoria forms (13.4% of the sample) contained speed data. The data came primarily from the Bell Park neighborhood and showed actual speeds over the posted limit ranging from 7 mph to 18 mph.
6In retrospect, this was probably a poor decision on the part of this project. It was assumed that the police would not want to publicize their decision-making and so no data category was included. As data collection progressed, it became clear that the participating police would have been willing to record the information. At that point, the Phoenix police participants agreed to ask all involved officers to write in the information.