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54 Automatic monitoring of vehicle condition was cited by Empirical data (e.g., those related to divided and undivided several case study interviewees as a growing application with highways and traffic density) demonstrate that the cate- both safety and efficiency benefits. Onboard monitoring of gory (d) does affect crash risk strongly. For the other expert vehicle condition complements and extends the high-quality respondents, choice (d) was at the middle of the five factors vehicle maintenance programs of many top fleets. Tire pres- with regard to its effects on crash risk. sure monitoring exemplifies truck vehicle condition moni- toring. In the LTCCS, 1.1% of at-fault truck crashes were Most of the specific driving situations and operational prac- caused primarily by tire failure, which is usually the result tices presented to both respondent groups received positive of underinflated tires. A 2003 study of truck tire inflation ratings for safety. "Maximizing travel on low-speed roads," by Kreeb et al. found that fleet maintenance of tires was presented as the opposite of "maximizing travel on Interstates often poor, resulting in high rates of tire underinflation. and other freeways," received the highest negative ratings. Improper inflation raised tire-related costs by $600 to $800 Day driving was favored over night driving by both respon- annually per tractor-trailer combination. About 5% of fleets dent groups, but with disagreement by some respondents. The currently use onboard tire pressure monitoring systems. A two contrasting items on truck size generated the widest vari- recent fleet test of tire pressure monitoring systems found ation of responses and disagreement. Although using "fewer, their use to be associated with slower tire wear and 1.8% larger trucks" received slightly higher mean ratings by both better fuel economy. groups, there was no consensus. PM was the most widely prac- ticed and rated carrier risk-avoidance practice. What about the general relationship between efficiency and safety? Do the various efficiency practices add to greater safety? Do carrier practices that foster efficient operations REPORTED EFFECTIVE CARRIER PRACTICES also foster safe operations? The project did not measure either the efficiency or safety of any fleet, so it cannot provide defin- The project evidence and product review (chapter two), sur- itive evidence. A survey question asked respondents about the veys (chapter three), and case studies (chapter four), as well general relationship. Strong majorities of both categories of as past reviews, indicate the following as common and bene- respondents believed that, "Highly efficient carriers tend also ficial carrier practices for consideration: to be more safe than other carriers." Other studies suggest a positive relationship between systematic, high-performance Operational planning and pre-trip actions (i.e., many of company management and worker safety. This is especially the strategies discussed herein) to reduce crash risk sys- true if company efficiency and growth can be achieved with- tematically; out putting excessive productivity and delivery pressure on Pre-trip planning for individual trips, to include routes drivers. Survey comments reinforced the notion of a positive and schedules, including planned rest stops; relationship, with the same caveat about avoidance of exces- PM schedules and records for each vehicle, aided by sive stress on drivers. maintenance management software; Aggressively reducing empty backhaul trips for finan- By and large, the safety-manager and other-expert survey cial benefits and to reduce unnecessary risk exposure; responses paralleled the findings of the literature review on Reducing loading and unloading delays by working various report topics. A top-level exception, however, was with shippers and receivers and by changes in carrier seen in the results of the opening survey questions on gen- operations; eral factors affecting crash risk. In Questions 1 and 2 (for both safety managers and other experts), respondents were Optimizing routing for individual vehicles and whole asked to select from the following the two factors with the operations. Expedited travel through improved routing greatest general effect on crash risk, and the one factor with generally translates into safety gains as well; the least effect: Providing truck-specific navigational aids to drivers; Assigning familiar routes to drivers when possible; (a) Enduring driver traits; Routing vehicles through divided, limited-access roads (b) Temporary driver states; (e.g., Interstates) when feasible, even at the expense of (c) Vehicle characteristics and mechanical conditions; extra miles; (d) Roadway characteristics and traffic conditions; and Avoiding highway work zones when feasible; (e) Weather and roadway surface conditions. Avoiding urban areas when feasible, in particular dur- ing morning and evening peak hours; For safety managers, the vehicle-related choice (c) received Avoiding adverse weather and slippery road surfaces the fewest "most" votes, whereas choice (d), "roadway char- when feasible; acteristics and traffic conditions," received the greatest num- Using onboard computers and mobile communications ber of "least" votes. Thus, both (c) and (d) could be regarded for driver monitoring and to support operational effi- as "losers." Ironically, perhaps, choice (d) has the greatest ciencies, but with measures to ensure that drivers are not relevance to the current study, because many operational distracted while driving; transport efficiencies related to roadway and routing choices. Using speed limiters;