HD17 - Passenger Vehicle Crashes Into Stationary Large Trucks: Incidence and Possible Countermeasures


Executive Summary:
House Joint Resolution No. 23, 2002 Session, requested that the Virginia Transportation Research Council and the Crash Investigation Team of Virginia Commonwealth University’s Transportation Safety Training Center conduct a study of highway crashes involving trucks and other large vehicles stopped on the roadway or shoulder and struck in the rear. The purpose of the study was to determine what spatial and perceptual factors, physiological elements, and ingredients combine to cause or materially contribute to these crashes; how and why crashes of this type happen; and what recommendations might be useful and practical to reduce the number and severity of these crashes.

In answer to the question of how and why these crashes happen, data concerning Virginia crashes from 1997 through 2001 were analyzed to develop descriptive statistics. Crashes in which a large truck stopped on the roadway or shoulder was struck in the rear by a passenger vehicle represent a very small subset of the total crashes in Virginia. Rear end crashes in which the leading vehicle was stopped were more numerous, but single-vehicle roadway departure crashes into parked vehicles were more severe. Environmental, roadway, and surface conditions had little influence on these crashes. The major contributing factor to these crashes was driver inattention.

The answer to the question concerning psychological and perceptual factors contributing to these crashes is less clear. It is likely that large trucks are more conspicuous than other stopped vehicles because of their size, unique profile, and requirements for reflectorized tape. However, large trucks stopped or parked continue to be struck in the rear by passenger vehicles. The cause here is also driver inattention but in one of several forms including lack of vigilance, driver distraction, steering toward a target, and insufficient visibility or too few visual clues, none of which can be directly attributed to any particular crash without a detailed crash investigation.

In answering the question regarding what countermeasures might be practical and useful, two approaches stand out: increasing driver attention and removing large trucks from the shoulder. Existing methods for increasing driver attention include using variable message signs and continuous shoulder rumble strips. Future improvements to driver attention are linked to technically advanced collision warning systems that will enter the marketplace before 2012 and provide an automatic warning to drivers of possible collisions. Removing large trucks from the shoulder is more of a problem and is tied to the larger issue of the supply and demand for public and private commercial vehicle parking. The study presents the following recommendations to address the findings and conclusions.

Recommendations

Countermeasures Involving Federal and State Regulations

1. The Commonwealth should amend COV 46.2-111 (Flares and Other Signals Relating to Disabled Vehicles) so that it applies to both disabled and roadworthy vehicles on any roadway and the shoulders of any roadway.

2. The Commonwealth should strictly enforce all state regulations and Federal Motor Carrier Safety Regulations enumerated in 49 CFR, Parts 390 through 397 (included by reference in 19 VAC 30-20-80).

3. If COV 46.2-111 is amended, enforcement officials should issue all citations for illegal truck parking on the shoulder under the new violation if it applies.

Countermeasures Involving Large Truck Parking

4. Since the number of truck parking places in public rest areas on I-81 is insufficient to meet the demand according to FHWA (2002) and Garber et al. (2002), VDOT should develop in conjunction with Truck Fleet Support and 511 Virginia a pilot application for a real-time information system designed to track the number of nearby commercial parking spaces available and make this information available to truckers, either in vehicle, at the rest areas, or on interactive highway signs.

5. The Virginia DMV should investigate the feasibility of opening Virginia’s weigh stations for truck parking 24 hours a day.

Issues Involving Accident Reporting

6. The Virginia DMV and the interagency group amending the FR 300 report form should consider making provisions to include underride information in the new report form and coordinate the coding of SVRD and on-road rear-end crashes to improve the consistency of data collection.

7. To improve the quality of crash data captured by the FR 300, enforcement officials should receive more training on accident reporting procedures focusing on SVRD crashes and underride involvement. Further, the Police Officer's Instruction Manual for Investigating Traffic Accidents should be modified to provide additional information concerning SVRD crashes and underride involvement.

Issues for Further Research

8. An investigation of Virginia’s existing crash database should be undertaken to determine the precision and reliability of the data elements and to allow recommendations for amended coding procedures.

9. To gain a more accurate picture of the number of commercial motor vehicles illegally parked, a study should be conducted to determine the extent of large truck parking on ramps and shoulders of Virginia’s limited access highways.

10. A feasibility study should be conducted on methods (other than rumble strips) to clearly identify shoulders, including their cost-effectiveness.

11. A statewide study should be conducted to assess the adequacy of large truck parking spaces in Virginia and to prioritize locations with the greatest need for public and private development.