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25 ICF International 2007). Team driving has several important monitor commercial driver HOS compliance by maintaining a safety advantages, but also some disadvantages. Knipling readable electronic time record of vehicle movement (driving) (2006, 2009) summarized the advantages and disadvantages as and of time duration since the day's initial driving. EOBRs are follows: used voluntarily by a growing number of CMV fleets, but are currently required only for those carriers with the worst histo- Safety advantages: ries of HOS noncompliance. FMCSA is considering extending Presence of second person in vehicle reduces unsafe the EOBR requirement to a larger percentage of noncompliant driving acts; carriers. This discussion addresses only the efficiency and Social interaction sustains alertness; safety management benefits of EOBRs, not regulatory issues Reduced continuous-time driving (time-on-task); surrounding them. Sleep and breaks can be on demand; Greater regularity of sleep; Apart from EOBRs' effects on HOS compliance and driver Greater overall sleep time; and fatigue per se, they are seen by some fleets as an aid to more Familiar and secure sleep location. efficient operations and to safety management. Eight of the Safety disadvantages: 11 case study carriers (see chapter four) either were using Poorer quality of sleep in moving vehicle; EOBRs or were transitioning to them, and most considered Shorter durations of principal sleep period; and them beneficial for both safety and efficiency. Because Possible greater fatigue at start of trip (if driver sleep EOBRs automate driver log-keeping, they save drivers' time, schedules are not coordinated). streamline records and compliance management, and provide a means for safety oversight of drivers through quick identifi- Team driving appears to have lower crash risk than solo cation of noncompliant drivers. EOBRs also facilitate load driving. A naturalistic driving comparison of team and assignments in larger fleets by identifying drivers with suffi- solo driving (Dingus et al. 2001; FMCSA 2002) found the cient time available for the loads. One corporate vice presi- team driver incident rate to be less than one-half of the solo dent for safety interviewed in conjunction with the study driver rate. Team drivers had far fewer driving misbehaviors noted that EOBRs help carriers to "draw a line in the sand" in such as speeding and tailgating. Although sleep quality was their interactions with customers. Customers might assume lower for team drivers (because they were sleeping in moving that paper logs allow HOS compliance flexibility, whereas vehicles), sleep times were longer. The team driver rate of EOBRs reinforce a need for absolute compliance. high-drowsiness incidents was just one-fourth the solo driver rate. Team drivers were much less likely to push themselves Shackelford and Murray (2006) found EOBR benefits to the limit and therefore avoided high-drowsiness incidents. included improved fuel consumption monitoring and fuel tax compliance, quicker tabulation of driver mileage and loads, Team driving presents management and operational chal- easier tracking of vehicle and engine wear, real-time vehicle lenges, however. Many carriers would utilize team driving location monitoring, and better communications and dispatch- more extensively if they could better meet these challenges. ing. The study even reported improved driver morale. Questions and challenges relating to team driving involve trip planning and routing, vehicle features (i.e., sleeper berths), team driver recruiting and assignments, daily work and driving sched- FUEL ECONOMY AND SAFETY ules (e.g., use of split sleep), and safety management practices. Married couples generally make the best and happiest driver Another carrier efficiency factor with safety implications is teams because of the close driving and living conditions. fuel economy. Several interviewees believed their efforts to improve fleet fuel economy had safety benefits. Maximizing No item addressing team driving was on the safety-manager fuel economy has cost-reduction benefits for companies and survey form, but one was added to the other-expert form. the environmental benefit of reducing emissions. Devices Respondents rated the item "Maximize use of driver teams and driving practices improving fuel economy also reduce for long hauls" on a -3-to-+3 Likert scale. The mean rating vehicle wear, tire wear, and maintenance costs (Smith and assigned by 31 respondents was +0.8, equal to the grand Roberts 2007). Improved fuel economy is achieved in large mean rating for the 16 items rated. Only one of the 11 case part by changes in vehicle speed and driving style. These study interviewees explicitly mentioned team driving as a changes in turn produce safety benefits such as reduced safety strategy; the Carrier B interviewee noted his com- driver stress, crash likelihood, and crash severity. Two primary pany's support for it as both a safety and efficiency measure. approaches to improving fuel economy that have concomi- tant safety benefits are speed-limiting vehicles and monitoring individual driver fuel consumption. ELECTRONIC ONBOARD RECORDERS The topic of EOBRs was not within the original scope and was Speed Limiters not included in project surveys. However, EOBRs are dis- cussed briefly because they were cited by several case study Speed limiters, also called speed governors, are devices that interviewees as aids to both efficiency and safety. EOBRs limit the top powered speed of vehicles. Modern truck engines'

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26 electronic control modules are easily programmed to limit top Fuel economy can also be monitored conventionally with- powered speeds to some set point. And, because "excessive out special onboard capabilities. Internationally, an initiative speed" was the most frequent proximal cause of truck crashes called ecodriving (www.ecodrive.org) is promoting greater in the LTCCS, some might regard speed limiters as a top- fuel economy for all vehicles. Ecodriving focuses on driving priority crash countermeasure. One must realize, however, that style. Its "Five Golden Rules" are: speed limiters cannot prevent most truck crashes arising from excessive speed. That is because most instances of "excessive 1. Shift up as soon as possible. speed" occur on lower-speed roads and at speeds below top 2. Maintain a steady speed. freeway speeds (e.g., 65 mph). Moreover, speed limiters would 3. Anticipate traffic flow. not slow the downhill speeds of trucks. Speed limiters would, 4. Decelerate smoothly. however, reduce both the likelihood and severity of crashes 5. Check tire pressure frequently. involving trucks and buses traveling at speeds greater than the top freeway speeds. With the exception of Rule 1, all of the rules for improved fuel economy are also rules for safer driving. Ecodrivers are CTBSSP Synthesis 16 (Bishop et al. 2008) examined the "smooth operators." They learn to adopt a smoother driving safety impact of large-truck speed limiters. The project style, "gliding" through traffic, shifting to the highest gear included a safety-manager survey based on a convenience possible, and avoiding rapid accelerations and decelerations. sample, similar to the current study survey. In the MC-16 proj- Drivers learn to look down the traffic stream as far ahead as ect survey, 56% of respondents indicated speed limiters were possible to predict and react smoothly to changes and inter- either "successful" or "very successful" in reducing crashes. ruptions in traffic flow. This defensive, anticipatory driving Speed limiter users believed that limiters were either "suc- style also serves to reduce crash risk. cessful" or "very successful" in reducing tire wear (44%) and increasing fuel economy (76%). Almost 96% of respondents In the United Kingdom, more than 13,000 heavy vehicle believed that speed limiters had no negative effects on either operators have received ecodriving training, with a reported their company's safety or productivity. average fuel savings of 10% (SAFED 2010). Symmons and Rose (2009) described an ecodriving training program in a Speed limiters are already required on trucks in European trucking fleet that reduced fuel consumption by 27%, gear Union countries and in Ontario and Quebec in Canada. In the changes by 29%, and brake applications by 41%. Another United States, NHTSA and FMCSA have proposed federal ecodriving training and monitoring program reportedly regulations for speed-limiting heavy trucks, and the matter resulted in a 13% fuel savings at Setz Transport Company is under rule-making consideration. Much of the trucking (IRU 2003). The Setz program involved fuel consumption industry favors mandatory speed limiters on large trucks monitoring, positive recognition for drivers showing improve- (ATA 2006), and many companies are adopting them volun- ments, and remedial training for those not showing improve- tarily (Bishop et al. 2008). Reduced crashes are the primary ment. A 2007 TRB paper (Zarkadoula et al. 2007) described rationale, but other reasons include lower fuel and mainte- a successful pilot test of ecodriving involving urban bus nance costs, reduced emissions, and longer tire life. The proj- drivers in Greece. The SAFED (2010) bus and coach web ect survey included no items on speed limiters, but some page reported 12% fuel savings, a 40% reduction in gear respondents and case study interviewees commented on their changes, and a 60% reduction in "safety-related faults," efficiency and safety value. No quantitative crash rate reduc- although the latter was not defined or explained. tions were reported, though one earlier study accessed in the literature review found that trucking firms with firm speed The term "ecodriving" is commonly used in North Amer- limit policies had crash rates 30% lower than those of their ica, but many fleets monitor fuel use for individual drivers. peers (Dammen 2005). Fuel use may be the basis for driver rewards, positive recog- nition, or discipline. Many companies use the same vehicle Several of the case study interviewees stated that their monitoring capabilities to measure hard-braking events, trucks were electronically speed limited, usually at 65 mph. which are themselves correlated with fuel consumption and Those mentioning speed limiting also stated that they moni- crash risk. Almost all of the project case study companies (see tored driver fuel use, as discussed next. chapter four) monitor individual driver fuel use and compo- nent behaviors such as hard braking and speeding. For exam- Monitoring Driver Fuel Economy ple, Carrier J (Small Charter Bus Service), a small charter bus company, has equipped all of its motor coaches with a multi- A more direct method for improving fuel economy is to mon- function electronic monitoring system. The system provides itor fuel use for individual drivers and trips. A capability for onboard safety monitoring (OBSM) of driving behaviors and onboard fuel consumption monitoring is commonplace in electronic HOS logs. The OBSM system records and reports today's trucks. Advanced, electronically controlled engines top speeding time (i.e., above a specified top speed), highest automatically monitor fuel consumption. Many EOBRs also observed speeds, hard-braking events and rate, fuel use, and monitor fuel consumption (Shackelford and Murray 2006). other driving efficiency and safety indicators. The system