Safety at the racetrack: results of restrictor plates in superspeedway competition.

• Author: O'Roark, J. Brian
• Position: Auto racing competitions

1. Introduction

   In May of 1987, driver Bobby Allison's car became airborne after blowing a tire in the front stretch of the Talladega Superspeedway in Alabama. The car destroyed 100 feet of safety fencing and nearly entered the densely packed grandstands at 210 miles per hour. As it was, debris from the airborne car caused severe injuries, including the loss of an eye by a spectator. Allison was not seriously injured, but the National Association for Stock Car Auto Racing (NASCAR) saw the horrific possibilities and implemented a plan to slow down cars at its two fastest speedways: Talladega and the Daytona track in Florida (Duskey 2001).

   NASCAR's solution was to mandate the use of restrictor plates at these tracks. This device limits the flow of air to the car's engine, thereby reducing the horsepower and, consequently, the speed the engine can generate. Since their introduction, restrictor plates have succeeded in reducing not only speeds reached during races, but also qualifying speeds. Prior to the implementation of the plates at Daytona and Talladega, qualifying speeds consistently exceeded 200 miles per hour (mph), reaching a high of 212.809 mph during the qualifying session in which Allison's infamous takeoff occurred. Since then, qualifying speeds have never reached 200 mph and have actually declined so that in 2000 and 2001, qualifying speeds averaged just under 187 mph. Despite achieving the objective of slowing down the cars, the use of restrictor plates has been controversial among drivers, many believing that their personal safety has been compromised. The refrain from many NASCAR drivers is that during a restrictor-plate race, "the big one" is inevitable, and hopefully no one will be seriously injured. Veteran Sterling Marlin voiced a common concern among NASCAR drivers after a last-lap crash at the Talladega race in October 2001 eliminated 16 of 43 cars: "They [restrictor plates] caused this and they'll continue to cause things like this until they [NASCAR officials] get them off the cars. It's not safe and they better do something" (Associated Press 2001).

   This article investigates the empirical determinants of safety at NASCAR races, paying particular attention to the effects of restrictor plates. No one debates that spectator safety is now greater; however, if, as the drivers assert, their well-being is diminished, then NASCAR finds itself in the unenviable situation of placing its product in jeopardy for the safety of its fan base. What we seek to determine is whether, in fact, restrictor-plate racing is more hazardous than non-plate racing. We establish a model that evaluates not only the relationship between restrictor plates and driver injuries, but also between the plates and accidents on the track. It may be the case that what drivers are actually observing is more cars wrecking on the track and not necessarily an increased threat to their personal safety. If this is the case, then NASCAR may have happened upon a process for increasing fan interest in these races. When more cars wreck, viewership increases, while the drivers themselves are not harmed. NASCAR veteran driver Bobby Labonte sarcastically summed this up, saying, "The grandstands are full and everybody is OK, so I guess it's OK" (Associated Press 2001).

   As we proceed with our analysis, section 2 examines the highway safety literature and makes a connection with our NASCAR data. Section 3 details the data, and section 4 sets up the model describing the number of wrecked cars. Section 5 expands the model to evaluate driver injuries. Finally, we summarize our findings in section 6.

2. Does Speed Kill or Does Variance Kill?

   Research into NASCAR safety can he seen as an extension of highway safety studies, although in a highly controlled or even artificial setting. NASCAR races provide experiments in risk and safety in addition to entertainment. The data are cleaner than highway data, however, due to a number of differences. First, weather conditions are eliminated as a major influence on safety at NASCAR races, as races are postponed in rain and are never run in ice or snow. There are few threats of wildlife on the track, though deer have been known to wander onto the Pocono Speedway in Pennsylvania, and driver Dale Earnhardt once hit a seagull during a race. Furthermore, there are no drunk drivers at NASCAR races. Finally, and perhaps most importantly, the drivers are all professionals and acutely aware of the risks inherent in their profession.

   The use of restrictor plates to slow the competitors naturally raises two questions, both having been extensively researched in the highway traffic safety literature. The first issue considers what Peltzman (1975) calls offsetting behavior. The second angle concerns the question of whether "speed kills," that is, whether accidents, injuries, and fatalities are more likely when speed is higher, other things equal.

   Peltzman's seminal article shows that, as drivers feel safer in their cars, they tend to offset the reduction in potential injuries by driving more aggressively, thus inducing behavior that leads to more severe accidents for both the operator of the vehicle and pedestrians. In other words, regulations enacted to make drivers safer have been offset by increasingly reckless driving, thus shifting the accident affliction to pedestrians as shown using time series data. However, a cross-sectional model suggests that regulations precipitated an already developed downward trend in accidents. These regulations have resulted in fewer yet more severe accidents. Peltzman's main point is that the unintended consequences of the National Traffic and Motor Vehicle Safety Act of 1966 have been ignored, obviously, creating a good deal of consternation for those who advocate safer automobiles.

   Robertson (1977) contradicts the offsetting behavior hypothesis by suggesting that Peltzman's model was not only incorrectly constructed, but also contained an omitted variable bias. Once the bias is corrected, Robertson finds no indication of increased risky behavior. Graham and Garber (1984) agree and show Peltzman's model to be fragile. Their version suggests that tens of thousands of lives were saved as a result of safety standards implemented by the National Traffic and Motor Vehicle Safety Act. Additionally, they show no increase in pedestrian deaths as predicted by Petlzman.

   More recently, support for Peltzman has increased. Chirinko and Harper (1993) illustrate that offsetting behavior is indeed a concern in evaluating the severity and incidence of injuries in an increased safety-standards world. However, they concede that determining the cause of this offsetting behavior is difficult. Risa (1994) explores the presence of offsetting behavior in Norway. His conclusions indicate that the degree of risk that a driver is willing to undertake with the installation of a new technological innovation is instrumental in explaining the proportion of offsetting behavior. Sobel and Nesbit (2003) apply Peltzman's model to the NASCAR realm, concluding that using this micro-level data, offsetting behavior occurs due to increased safety features. In other words, as safety features have been added to cars, accidents have become more prevalent.

   Though Peltzman's position focuses on offsetting behavior that results from the increased likelihood of a driver avoiding injury, the question that we are concerned with focuses on a safety feature that, as many of the NASCAR drivers contend, does not increase the safety of the driver. Instead, in Peltzman's terms, restrictor plates exist to prevent harm to bystanders, specifically fans. We therefore move to the second issue: the "speed kills" branch of the highway safety literature that provides additional background for our model.

   During the debate over a national 55-mph speed limit, Lave (1985) proposed that it is not speed that kills, but rather variance of speeds that is more deadly. In his data analysis, there was no statistically significant relationship between speed and fatality rates. Though speed limits are often viewed as a constraint to behavior, in Lave's view, coordinating rather than limiting behavior may be more important. Thus, apart from...