In 1995, Congress issued a mandate requiring that the safety record of commercial vehicles and drivers be used as a guide to selecting vehicles and drivers for roadside inspections. The "Aspen roadside inspection computer software system" was developed in response to the mandate. The system "helps conduct roadside driver and vehicle inspections with portable microcomputers, including those with hand-held pens." Part of the system, called the "Inspection Selection System (ISS)," was recently evaluated for overall effectiveness. Brenda M. Lantz, Michael W. Blevins, and Thomas J. Hillegass reported the evaluation's results in "Evaluation of Roadside Inspection Selection System for Commercial Vehicles" (Transportation Research Record 1595). They concluded that, with "consistent use," the ISS would have a number of benefits, including "substantial" safety benefits--estimated at around $60 million each year.

BACKGROUND

The ISS was born of the knowledge that trucking companies "with high roadside inspection out-of-service (OOS) rates are more likely to have conditional or unsatisfactory safety compliance fitness ratings and higher accident rates." Therefore, OOS rates are good indicators of a company's "safety fitness." The generally accepted standard is three inspections in two years. In a recent two-year period (1994-1996), 40.5 percent (107,455) of companies had no roadside inspections, and 27.5 percent (73,084) had only one or two inspections. In the same two-year period, the companies that met or exceeded the three-inspection standard generally had lower OOS rates.

The ISS was designed at the Upper Great Plains Transportation Institute at North Dakota State University, in cooperation with the Federal Highway Administration (FHWA) and a "10-state roadside Technology Technical Working Group (TWG)." The goal of ISS was to "better distribute roadside inspections" among trucking companies and "target those with prior poor safety performance." Most states now use the ISS.

During a typical roadside inspection, the inspector enters the vehicle's Department of Transportation or Interstate Commerce Commission number into a microcomputer running ISS software. Based on the company's safety record, the computer then displays an inspection value and a recommendation. The ISS also provides recommendations based on previous problems, thus "suggest[ing] that the inspector focus on those areas with a known history of violations." While the system makes recommendations for inspection, "it should be emphasized that the ISS, either within Aspen or as a stand-alone system, is only a tool for the inspector. The final decision about whether to inspect the vehicle or driver is always made by the inspector."

METHODS

The ISS development evaluation used data from inspections of interstate trucking companies in the ten TWG states during January through March 1996. The evaluation included only pen-computer inspections, since only they "would definitely have received an ISS inspection value and a recommendation for the inspector." ISS calculated inspection values for just over 93 percent of the inspections using pen-computers, for a total of 7,142 inspections used in the first part of the evaluation. A follow-up evaluation in September 1996 used data from inspections conducted from January through August 1996. Slightly more than 92 percent of these had an ISS inspection value, for a total of 39,819 inspections during the eight months.

The authors compared those companies recommended for inspection and those that were not. On average, they expected those recommended for inspection to have higher OOS rates and lower inspection rates. The evaluation also included a survey of inspectors in the TWG states "to assess their perceptions of Aspen and the ISS program."

RESULTS

Results showed "significant difference[s]" in both the driver and vehicle OOS rates for those trucking companies "stopped for inspection with ISS inspection values greater than 80 (that is, those recommended for inspection) versus those stopped with ISS inspection values less than 80." On average, companies recommended for inspection had an 11 percent OOS driver rate and a 34 percent vehicle OOS rate, compared with a 7 percent OOS driver rate and 15 percent vehicle OOS rate for companies not recommended for inspection. In addition, "6.4 percent . . . of the inspections conducted on carriers with ISS inspection values greater than 80 were on carriers with fewer than three previous inspections," compared "with 1.0 percent . . . of the inspections that were conducted on carriers with fewer than three previous inspections when the ISS did not recommend the inspection."

The evaluation's authors also "wanted to know whether more vehicles and drivers would be put OOS when the ISS recommended the inspection." (Again, companies with an ISS inspection value less than 80 were not recommended for inspection, while those with a value greater than 80 were recommended for inspection.) Table 1 shows those "dramatic" results. During the three months, more than a third (38.2 percent) of the drivers or vehicles recommended for inspection "were actually put OOS."

Table 2 shows the "remarkably similar" results from the January-through-August analysis.

A total of 168 inspectors completed the survey, and "answers differed substantially among the states." The inspectors "had a wide range of experience with Aspen and the ISS program, ranging from 2 weeks to more than 2 years." Sixty-four percent felt the ISS inspection values were "somewhat to very accurate," and just over 71 percent "indicated that Aspen and the pen-computer itself were somewhat to very helpful in the inspection process." Just over 77 percent would recommend Aspen and the pen-computers to other states. Twenty-six percent used the ISS system in deciding whether to inspect a vehicle or driver, and just over 54 percent "indicated that it was somewhat to very helpful to them." When asked if they would recommend the ISS to other states, 70.1 percent indicated they definitely would.

BENEFITS

The ISS system holds the potential for several benefits, including the ability to obtain data on companies with little or no previous information. Safe trucking companies that are no longer stopped for inspections could reap substantial cost savings through use of the ISS, because the cost of inspections would be "diverted" to companies with poorer safety histories or no safety history at all. Using a conservative cost estimate of $10.67 for each of the roughly two million inspections conducted each year, companies with a good safety record would save about $7.1 million each year. In addition, "a 60 percent increase in the number of drivers or vehicles put OOS would definitely have a significant impact . . . on safety for society as a whole." Taking "into account fatalities, injuries, property damage, traffic delays, and business disruptions that are avoided because of roadside inspections," the benefits are estimated at $62.8 million each year.

CONCLUSIONS