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From page 1...
... A principal audience for the synthesis study will be managers of bus and truck fleets. However, the results will be of special interest to academic and trade association researchers in the field of motor carrier safety, and federal and state agency officials with responsibility for developing effective regulatory and incentive programs to enhance commercial motor vehicle safety.
From page 2...
... Even for the general driving population, it is uncommon to find studies that show a significant increase in crash risk for persons age 70 or younger. The literature review also suggests that, even with the physical and cognitive changes in older persons, older drivers can often compensate for those changes by making better decisions and demonstrating better judgment while driving.
From page 3...
... The team also planned to conduct surveys of commercial truck carriers, motor coach companies, school bus associations and companies, industry organizations (e.g., ATA) , insurance companies, state departments of transportation (DOTs)
From page 4...
... 4 A principal audience for the synthesis study will be managers of bus and truck fleets. However, the results will be of special interest to academic and trade association researchers in the field of motor carrier safety, and federal and state agency officials with responsibility for developing effective regulatory and incentive programs to enhance commercial motor vehicle safety.
From page 5...
... . In the physician's office, impaired vision attributable to cataracts may be detected through static acuity and contrast sensitivity tests, using eye charts; and impairments in visual function related to cataracts may be revealed through patients' questionnaire (VF-14)
From page 6...
... . Two studies that found an elevated crash risk for glaucoma patients included individuals with moderate to severe disease, who had significant visual field loss (<100 degrees total horizontal field)
From page 7...
... Sleep apnea patients, specifically, have been associated with a twofold to a sevenfold increase in crash risk, depending on the study (Teran-Santos et al.
From page 8...
... The risks of polypharmacy include an increase not only in the number of potentially inappropriate prescriptions, but also in cognitive disorders, depression, and an increased risk of motor vehicle crashes, as discussed later. As LeRoy and Morse (2008)
From page 9...
... Data describing the crash risk associated with therapeutic classes of prescription drugs are rare, and are not specific to commercial vehicle operations. LeRoy and Morse (2008)
From page 10...
... For example, because the visual acuity test is already universally applied for private vehicle as well as commercial vehicle operators [Ref.
From page 11...
... Attempts to quantify the safety impact of hearing loss for commercial vehicle operators remain inconclusive, as the FHWA hearing standard ensures that the same "restriction of range" for this functional ability applies as in the case of visual acuity. But in the private vehicle fleet, where this driver ability is not regulated, a relative risk associated with hearing loss has been demonstrated.
From page 12...
... However, they did find that a composite measure including contrast sensitivity, binocular visual acuity, and horizontal field measurement was significantly related to crash involvement for drivers age 66 and older. Failure on a combined criterion that incorporates a binocular acuity standard of 20/40, a horizontal visual field standard of 140 degrees, and below-normal scores for one or more of the three spatial frequencies of sine wave gratings in a contrast sensitivity test using a countertop vision tester produced the strongest relationship linking poor vision and high crash involvement, especially for the ages 66–75 and age 76+ driver groups (Decina and Staplin 1993)
From page 13...
... . Even as the relationship between visual field loss and crash risk remains difficult to quantify, given existing controls to remove those with severe deficits from the fleet, it is crucial to distinguish reduced visual field size or sensitivity as a sensory function from the related component of visual attention commonly termed "useful field of view." This is actually a perceptual-cognitive ability, for which reliable age differences and a significant relationship with at-fault crashes have been demonstrated, as discussed in the following section.
From page 14...
... Comparing performance on this test to California Department of Motor Vehicle crash records, poor performance on the speed of processing subtest accounted for 2.8% of the variance in crash involvement (p < 0.05) for drivers age 70 and older, without adjusting for demographics or driving exposure.
From page 15...
... on the useful-field-of-view subtest that measures divided attention were 3.11 times more likely to be in an at-fault crash in the 20 months following assessment than older drivers who performed well on the test. Looking at 20 months of prospective driving history data plus 1 year of retrospective driving history data, drivers performing poorly on the useful-fieldof-view subtest were 2.48 times more likely to be involved in a crash and 1.67 times more likely to be cited for a moving violation.
From page 16...
... Both of these measures were significant predictors of at-fault crashes in an observation period that included 1 year of retrospective crash data plus an average prospective observation interval of 20 months, for 1,876 drivers age 55 and older; their respective odds ratios were 2.64 (leg strength/mobility) and 2.56 (head/neck rotation)
From page 17...
... found that improvement in contrast sensitivity after cataract surgery was the best predictor of improved driving performance during an on-road (closed course) test, which included the ability to detect and avoid hazards.
From page 18...
... Driving performance data were collected using a TT150 Professional Truck Driving Simulator, configured as a cabover, tandem-axel tractor with a 48-ft trailer carrying an 80,000-lb uniform load with a high center of gravity. Structured observations of driver behaviors (e.g., mirror checks, visual search, and speed control)
From page 19...
... A case study of an early adopter of driver functional screening provides an example of how such screening can be implemented. The subject of this case study is Corry Auto Dealers Exchange (Corry ADE)
From page 20...
... With these limitations in mind, the potential benefits of driver functional screening to promote safety and advance risk management in commercial vehicle operations appear substantial. a routine functional screening program.
From page 21...
... were found at fault less than any other age group. Furthermore, of all 10-year age cohorts in the LTCCS, truck drivers ages 61 to 70 "had the lowest percentage of critical driver errors, by a wide margin" (Knipling 2009, p.
From page 22...
... The team also planned surveys of commercial truck carriers, motor coach companies, school bus associations and companies, industry organizations (e.g., ATA) , insurance companies, state departments of transportation, and other relevant organizations.
From page 23...
... However, much of that literature is based on research performed on significantly older persons than one finds in the commercial driver population. Even for the general driving population, it is uncommon to find studies showing a significant increase in crash risk for persons age 70 or younger.
From page 24...
... Bruni, "Visual Attention Problems as a Predictor of Vehicle Crashes among Older Drivers," Investigative Ophthalmology and Visual Science, Vol.
From page 25...
... Van Cott, and W.C. Rogers, Research to Enhance the Safe Driving Performance of Older Commercial Vehicle Drivers, NTIS PB96-176839, Office of Motor Carriers, Federal Highway Administration, U.S.
From page 26...
... Hedin, and J Tornros, "Effects on Driving Performance of Visual Field Defects: A Driving Simulator Study," Accident Analysis and Prevention, Vol.
From page 27...
... Bergoffen, CTBSSP Synthesis 5: Training of Commercial Motor Vehicle Drivers, Transportation Research Board, National Research Council, Washington, D.C., 2004. Staplin, L., K
From page 28...
... Wood, J.M., and T.P. Carberry, "Bilateral Cataract Surgery and Driving Performance," British Journal of Ophthalmology, Vol.
From page 29...
... Horsley, Executive Director, American Association of State Highway and Transportation Officials, Washington, DC Rose A McMurry, Acting Deputy Administrator, Federal Motor Carrier Safety Administration, U.S.DOT Ronald Medford, Acting Deputy Administrator, National Highway Traffic Safety Administration, U.S.DOT Victor M
From page 30...
... W ashing to n, d .C . 20001 A D D R eSS SeR ViCe R eQ UeSTeD TRB A Synthesis of Safety Practice Sponsored by the Federal Motor Carrier Safety Administration 1431417803099 ISBN 978-0-309-14314-1 90000 >


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