Elizabeth N Mazzae

DRIVER REACTION TIME IN CRASH AVOIDANCE RESEARCH : VALIDATION OF A DRIVING SIMULATOR STUDY ON A TEST TRACK

A series of experiments was conducted on the Iowa Driving Simulator to examine driver reaction and performance in an intersection incursion crash scenario. To validate these simulator trials, a second study was run on a test track using a similar intersection incursion scenario to examine driver reaction and vehicle performance. Results showed that there was statistical equivalence between important driver reaction times with both studies.

Driver Crash Avoidance Behavior with ABS in an Intersection Incursion Scenario on Dry Versus Wet Pavement

ABSTRACTThe National Highway Traffic Safety Administration(NHTSA) has developed its Light Vehicle Antilock BrakeSystems (ABS) Research Program in an effort todetermine the cause(s) of the apparent increase in fatalsingle-vehicle run-off-road crashes as vehicles undergo atransition from conventional brakes to ABS. As part of thisprogram, NHTSA conducted research examining drivercrash avoidance behavior and the effects of ABS ondrivers’ ability to avoid a collision in a crash-imminentsituation. The study described here was conducted on atest track under dry and wet pavement conditions toexamine the effects of ABS versus conventional brakes,ABS brake pedal feedback level, and ABS instruction ondriver behavior and crash avoidance performance. Thisstudy found that drivers do tend to brake and steer inrealistic crash avoidance situations and that excessivesteering can occur . However, a significant number of roaddepartures did not result from this behavior for eitherpavement condition. ABS was found to reduce crashessignificantly on wet pavement as compared to conventionalbrakes.INTRODUCTIONSince 1985, antilock brake systems (ABS) have beenincreasingly available on many passenger car and lighttruck make/models. ABS have been sold as an addedsafety feature which enhances drivers’ ability to control avehicle and, in some cases, improves vehicle stoppingperformance. In the interest of reaping the benefits ofABS in terms of a reduction in crashes, the HighwaySafety Act of 1991, Section 2507 charged the NationalHighway Traffic Safety Administration (NHTSA) with thetask of determining whether ABS should be required on allpassenger vehicles.As a result, NHTSA undertook a series of investigations todetermine the potential benefits of ABS and the effect ofABS on crash rates. Test programs have shown that ABSappear to be very promising safety devices whenevaluated on a test track. Under many pavementconditions antilock brake systems allow the driver to stopa vehicle more rapidly while maintaining steering controleven during situations of extreme, panic braking. Brakeexperts anticipated that the introduction of ABS onpassenger vehicles would reduce both the number andseverity of crashes. However, a number of crash dataanalyses have been performed in recent years by NHTSA,automotive manufacturers, and others which indicate thatthe introduction of ABS has not been found to beassociated with a reduction in crashes to the expectedextent. CRASH DATAKahane [1] found that, with the introduction of ABS,involvements in mutli-vehicle crashes involving fatalities onwet roads were significantly reduced by 24 percent, andnonfatal crashes by 14 percent. However, thesereductions were offset by a statistically significant increasein the frequency of single-vehicle, run-off-road crashes, ascompared to cars without ABS. Run-off-road crashes, asconsidered in this report, included rollovers, side impactswith fixed objects , and frontal impacts with fixed objects.Fatal run-off-road crashes were up by 28 percent andnonfatal crashes by 19 percent. On wet roads, fatal run-off-road crashes increased 17 percent and non-fatal run-off-road crashes increased by 24 percent. On dry roads,fatal run-off-road crashed increased by 29 percent whilenon-fatal crashes increased by 17 percent.Hertz, Hilton, and Johnson [2] presented results forpassenger car run-off-road crashes according to thefollowing crash types: rollovers, side impacts with parkedvehicles or fixed objects, and frontal impacts with parkedvehicles or fixed objects. For dry roads, ABS was found tobe associated with a 17 percent decrease in rollovercrashes, a 13 percent decrease in frontal impacts withparked vehicles or fixed objects, and a 7 percent increasein side impacts with parked cars or fixed objects. Forpedestrian crashes, ABS was associated wtih a 30 percentreduction on dry roads and a 10 percent reduction inunfavorable road conditions (i.e., wet, snowy, icy, gravel).In regards to only those crashes involving fatalities, ABSwas found to be associated with a 51 percent increase infatal rollover crashes on dry roads. For fatal side impact

Driver Crash Avoidance Behavior with ABS in an Intersection Incursion Scenario on the Iowa Driving Simulator

The National Highway Traffic Safety Administration (NHTSA) has developed its Light Vehicle Antilock Brake Systems (ABS) Research Program in an effort to determine the cause(s) of the apparent increase in fatal single-vehicle run-off-road crashes as vehicles undergo a transition from conventional brakes to ABS. As part of this program, NHTSA conducted research examining driver crash avoidance behavior and the effects of ABS on drivers’ ability to avoid a collision in a crash-imminent situation. The study described here was conducted on the Iowa Driving Simulator and examined the effects of ABS versus conventional brakes, speed limit, ABS instruction, and time-to-intersection (TTI) on driver behavior and crash avoidance performance. This study found that average, alert drivers do tend to brake and steer in realistic crash avoidance situations and that excessive steering can occur. However, this behavior did not result in a significant number of road departures.

INITIAL DRIVER AVOIDANCE BEHAVIOR AND REACTION TIME TO AN UNALERTED INTERSECTION INCURSION.

Initial driver avoidance behavior and reaction time to an unexpected intersection incursion was determined using a state-of-the-art motion-based driving simulator (Iowa Driving Simulator). The intersection used for the experiment was on a two-lane rural highway (55 mph speed limit) that controlled perpendicular (crossing) traffic by stop signs. The subject vehicle did not have to stop and had the right-of-way on the highway. At one of three possible start times, an intersecting vehicle began moving into the intersection in front of the subject vehicle. This incurring vehicle intersected from either the drivers left or right side. Ninety-six subjects participated in the study. Subjects in the shortest, most severe collision avoidance situation were significantly slower to react and equally likely to steer or release the accelerator pedal as the initial avoidance maneuver. Subjects in the longest, least severe collision avoidance situation often released the accelerator pedal and braked prior to steering. Gender differences are also discussed.

Hardware evaluation of heavy truck side and rear object detection systems

This paper focuses on two types of electronics-based object detection systems for heavy truck applications: those sensing the presence of objects to the rear of the vehicle, and those sensing the presence of objects on the right side of the vehicle

Human Performance Evaluation of Heavy Truck Side Object Detection Systems

This study examines the effect of right Side Object Detection Systems ( SODS) on the performance of commercial vehicle drivers as a means of assessing the impact of these systems on safety. SODS are collision warning systems which alert drivers to the presence of traffic alongside their vehicle within defined detection zones.

Human Factors Evaluation of Existing Side Collision Avoidance System Driver Interfaces

This paper presents an assessment of the driver interface component of side collision avoidance systems. It looks at the design of the interfaces, and recommendations are presented regarding ergonomically desirable or undesirable features. A preliminary set of driver interface performance specifications are listed.

Development of a Test Protocol to Demonstrate the Effects of Secondary Tasks on Closed-Course Driving Performance

To assess the relative distraction potential associated with a variety of in-vehicle tasks, we developed a test protocol that provides an objective basis for demonstrating the tradeoffs between primary and secondary task performance in driving. The protocol includes two summary scores, one representing driving performance and one representing secondary-task performance. Driving performance was evaluated on a 1.3-mile test course, which included straight and curved road segments, a signalized intersection, a simulated work zone, two changeable-message signs, and six unexpected events. Secondary tasks included mental arithmetic, reading, writing, phone dialing, CD changing, route-guidance destination entry, eating, drinking and grooming. Twelve subjects drove an instrumented vehicle for 9 or 10 timed laps of the test course, each while performing a different secondary task or none (baseline). On average, we found a 15% decrement in driving performance scores on laps in which subjects engaged in a secondary task. Driving performance decrements were observed on 88% of these trials. Differences were observed between different secondary tasks. The pilot test results demonstrate the potential usefulness of the test protocol for assessing tradeoffs between primary and secondary tasks in driving.