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50 of local transit agencies. This suggests that the databases pro- Table 30 shows the proportion of SSO incident records vided by the local transit agencies did not include all of the that were also included in the NTD. incidents that occurred over the time period examined. Since Approximately 34% of the records contained in the SSO duplicate records were noted (and removed from) the NTD, databases were also found in the NTD database; this percentage there may also be some additional near-duplicate spurious increased to 42% when the Utah TRAX records were omitted. records in the NTD data. Table 31 shows the proportion of NTD incident records that were also contained in the SSO databases. Approximately 31% of the collision records contained in Comparison of SSO and NTD Databases the NTD database were also present in the SSO database. Although the SSO agencies are not responsible for report- Although this statistic is similar to the proportion of SSO data ing data directly to the NTD, both rely on the local transit records found in the NTD, there is considerably more vari- agencies for their incident reports. In addition, the reporting ability observed between transit agencies. requirements for the NTD and SSO agencies had many sim- ilarities over much of the time period examined. Examina- Conclusion tion of the differences between the data records available to each can shed light on how the different reporting criteria This chapter had several basic objectives. It describes and used by each administration level over the years has affected compares the NTD, SSO, and local transit agency data. It con- the amount of data made available to them by the local tran- tains detailed analyses of the locations, types, and severity of sit agencies. Table 29 shows the number of data records con- accidents (crashes) reported in the NTD database. tained in both the SSO and NTD databases. Several implications are apparent. Firstly, it is desirable to In general, more transit incidents were reported by the achieve better consistency among the three reporting systems. local transit agencies to the NTD than to the SSO. This was Reporting should be both consistent and useful for researchers, unexpected as one would expect the reverse. One significant transit system administrators, and oversight organizations (SSO exception was the Utah TRAX database, which contained and FTA). Secondly, the highest number of crashes involves substantially more incidents than the NTD. However, closer same-direction LRVmotor vehicle collisions. Thirdly, the inspection revealed that the Utah TRAX database included a largest number of fatalities involves LRVpedestrian collisions. column indicating the NTD classification of each incident. Of These are the two areas, same-direction LRVmotor vehicle the 110 incidents, only 14 were classified as "Major" while 4 collisions and LRVpedestrian collisions, where right-of- were classified as "Suicide." Therefore, it is clear that in this way design, operating policies, and traffic controls should be case, the disparity was a reflection of a difference in reporting focused to reduce the number of collisions in both new starts requirements. and retrofit situations. Table 29. Number of records in SSO database compared to NTD. Number of Number of Incidents Incidents Agency Name Years Reported in SSO Reported in NTD Database Database California Public Utilities Commission (SSO) Los Angeles County Metropolitan Transportation 74 128 20022007 Authority Sacramento Regional Transit 33 64 20022007 District San Diego Trolley, Inc. 52 34 20022007 San Francisco Municipal 85 168 20022007 Railway Santa Clara Valley 28 15 20022007 Transportation Authority Utah TRAX 110 16 20042006 Total (SSO) 382 425

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51 Table 30. SSO data records included in the NTD. Agency Name Number of Number of % of SSO Years Incidents Incidents Also Incidents Also Reported in Reported in Reported in SSO Database NTD NTD Database Database California Public Utilities Commission (SSO) Los Angeles County Metropolitan Transportation Authority 74 38 51.4% 20022007 Sacramento Regional Transit District 33 14 42.4% 20022007 San Diego Trolley, Inc. 52 26 50.0% 20022007 San Francisco Municipal Railway 85 25 29.4% 20022007 Santa Clara Valley Transportation Authority 28 11 39.3% 20022007 Utah TRAX 110 16 14.6% 20042006 Total (SSO) 382 130 34.0% 20022007 Table 31. Proportion of NTD data records appearing in SSO database. % of Number of Number of Agency- Incidents Incidents Level Reported in Also Incidents Agency Name Years NTD Reported in Also Database for SSO Reported in Agency Database SSO Database California Public Utilities Commission (SSO) Los Angeles County Metropolitan Transportation Authority 128 38 29.7% 20022007 Sacramento Regional Transit District 64 14 21.9% 20022007 San Diego Trolley, Inc. 34 26 76.5% 20022007 San Francisco Municipal Railway 168 25 14.9% 20022007 Santa Clara Valley Transportation Authority 15 11 73.3% 20022007 Utah TRAX 16 16 100.0% 20042006 Total (SSO Data in NTD) 425 130 30.6% 20022007