Accident Analysis and Prevention 36 (2004) 457–469 Analysis and prediction of traffic fatalities resulting from angle collisions including the effect of vehicles’ configuration and compatibility Mohamed Abdel-Aty ∗ , Hassan Abdelwahab Department of Civil & Environmental Engineering, University of Central Florida, Orlando, FL 32816-2450, USA Received 3 April 2002; received in revised form 11 February 2003; accepted 13 February 2003 Abstract Although the rapid growth in light truck vehicle (LTV) sales, including minivans, sports utility vehicles (SUVs), and light-duty trucks, has not been associated with an overall increase in collisions or traffic deaths in the US, there is a need for a research program to determine whether particular types of collisions have become more frequent or injurious because of the increase in the percent of LTVs in traffic. This paper presents an analysis of the effect of the increasing number of LTV registrations on fatal angle collision trends in the US. The analysis investigates the number of annual fatalities that result from angle collisions as well as collision configuration (car–car, car–LTV, LTV–car, and LTV–LTV). The analysis uses the Fatality Analysis Reporting System (FARS) crash databases covering the period 1975–2000. Results showed that death rates differ based on the collision configuration. Time series modeling results showed that fatalities in angle collisions will increase in the next 10 years, and that they are affected by the expected increase in the percentage of LTVs in traffic. Forecast showed that the total number of annual deaths is expected to reach 6300 deaths by the year 2010 (an increase of 12% over 2000). Analysis into the configuration of the collision indicated the seriousness of angle collisions involving an LTV striking a common passenger car (LTV–car). A time series model illustrated the significance of time lag and percent of LTVs in traffic on the increase of this type of fatal collisions. Forecasts from the time series model indicated a 32% increase in deaths due to this type of collisions in the next 10 years. © 2003 Elsevier Ltd. All rights reserved. Keywords: Light truck vehicle; Time series analysis; Angle collisions; Traffic fatalities; Collision; Configuration; Traffic composition 1. Introduction As occupant protection offered by new passenger vehi- cles has improved, there has been growing concern about the harm that some vehicle designs may inflict on occupants of other vehicles with which they collide. In vehicle-to-vehicle collisions, the protection of all occupants in the subject and other vehicle should be considered. This gives rise to the is- sue of vehicle compatibility. Compatibility means that pas- senger vehicles of disparate size provide an equal level of occupant protection in car-to-car collisions. The compati- bility of a vehicle is a combination of its collision worthi- ness (the car’s capability of withstanding the effects of a collision) and its aggressivity when involved in collisions with members of the vehicle fleet. The concept of com- patibility is well known not only in the safety commu- nity, but also by many automobile users. For example, in a two-vehicle collision, if one vehicle is deformed and the other vehicle is virtually undeformed, then the undeformed ∗ Corresponding author. Tel.: +1-407-823-5657; fax: +1-407-823-3315. E-mail address: mabdel@mail.ucf.edu (M. Abdel-Aty). vehicle is frequently considered to be the safest. A more obvious observation is that different bumper heights and dif- ferent vehicle geometry are considered leads to incompati- bilities. The vehicle fleet differs in mass, geometry, stiffness and many other parameters. These differences are consequences of different design objectives for these vehicles and re- sult from consumer demand, environmental, and safety consideration. A number of traffic safety studies (Faerber et al., 1998; Schoenburg and Pankalla, 1998; National Highway Traffic Safety Administration, 1998; Broyles et al., 2001) have examined the compatibility of light truck vehicles (LTVs) including light-duty trucks, vans, and sports utility vehicles (SUVs) with other common pas- senger cars in vehicle-to-vehicle traffic collisions. In gen- eral, three factors for vehicle-to-vehicle incompatibility are considered: 1. Mass incompatibility: Kahane (1997) has shown that LTVs are about 410 kg (900 lb) heavier than cars on average (Fig. 1). The conservation of momentum in a collision places smaller vehicles at a fundamental disad- vantage when the collision partner is a heavier vehicle. 0001-4575/$ – see front matter © 2003 Elsevier Ltd. All rights reserved. doi:10.1016/S0001-4575(03)00041-1