Driver depth perception and vehicle following distance in fog

Distance Perception of Vehicle Rear Lights in Fog

The purpose of this study is to assess the drivers' depth-perception in vehicle-following circumstances, and their connection with the reaction time for applying brakes and their ability to assess the actual distance of their vehicle from the leading vehicle. 50 participants will be chosen to perform this experiment, out of which, 25 will be male and 25 will be female. The experiment will take place in a foggy weather on a 15km section of a two-lane highway. It is expected that the drivers will maintain the minimum distance in relation to their speed and the speed of the leading vehicle. Also, it is expected that the drivers will maintain a minimum safe distance so that they can apply brakes in a timely manner. The study identifies the necessary patterns and methods that can offer substantial information on the subject of "depth perception."

Introduction

Depth Perception can be defined as "the visual ability to perceive the world in three dimensions. It is a trait common to many higher animals. Depth perception allows the beholder to accurately gauge the distance to an object (The American Heritage Dictionary, 2004)." The study of "Depth perception" has taken a major position in the research studies because majority of the road accidents occur due to inaccurate judgments about the distance of the vehicle in front. Majority of the research studies have utilized the following instruments to evaluate "depth perceptions:" Binocular vision, Motion parallax, Color vision, Perspective, Relative size, Distance fog, Occlusion, Depth from Focus (Cavallo V, Colomb M, Dore J, 2001; Johan W.A.M and Jan Theeuwes Alferdinck 1995 and Van Winsum and Heino 1996). This study will assume an important position on the subject of depth perception as the methodology of this experiment is unique and distinctive. Furthermore, while, many research studies have been unable to give a solution for the inaccurate judgment of depth perception, the number of accidents occurring due inaccurate judgment of depth perception has kept increasing. This study will surely be a concrete step towards finding the right solution as the potential application of this study is relatively comprehensive and broad.

Research Study 1:

Cavallo V, Colomb M, Dore J (2001) studied the influence of fog and a vehicle's rear-lights on the distance perception. In a foggy atmosphere, the participants gave their estimations on the perceived distance by assessing the distance of the rear lights of the car in front of them. While, an augmentation of about 60% had been observed in the perception of the car distance in fog, the estimation increased when the vehicle (in front) had only one rear-light instead of two. The results reveal the importance of having two rear-lights instead of one (Cavallo V, Colomb M, Dore J, 2001).

Research Study 2:

Johan W.A.M and Jan Theeuwes Alferdinck (1995) utilized clinical trials to evaluate the differences amid rear-light arrangements concerning procedures related to reaction time. The researchers measured the reaction as the time taken from the start of the lead vehicle's brake-lights to the taking-away of the participant's foot on the accelerator in the trailing vehicle. The results showed that the participants did not observe the brake-lights with complete attention and considerable variations were observed on the reaction time of various participants. The results reveal the importance of paying attention to the brake-lights of the leading car so that timely actions can be taken (Johan W.A.M and Jan Theeuwes Alferdinck 1995).

Research Study 3:

Van Winsum and Heino (1996) studied the available response time to the following vehicle should the lead vehicle decelerate, devoid of the speed of the vehicle. The participants were asked to apply brakes immediately after they observed deceleration of speed from the leading car. The results demonstrated that while the reaction time amongst the participants was different, it was fairly consistent for individual participants. The results reveal the variations in behavior patterns amongst different drivers (Van Winsum and Heino 1996).

The Subject under investigation

This study will assess the drivers' depth-perception in vehicle-following circumstances, and their connection with the reaction time for applying brakes and their ability to assess the actual distance of their vehicle from the leading vehicle.

Significance of the Study

The significance of this study can be gauged form the fact that research shows approximately 30% of all accidents occur due to inaccurate "depth perception" and lesser reaction time to apply brakes.

The Tasks and Variables Used

Each participant will go through three different blocks and each block will follow four trails so as to acquire accurate data. The participants will vary their speed in all the three blocks as each of the four trails (in the three blocks) will be executed at diverse speeds: 60, 70, 80 and 90 km/hr.

Expected Results

It is expected that the drivers will maintain the minimum distance in relation to their speed and the speed of the leading vehicle. Also, it is expected that the drivers will maintain a minimum safe distance so that they can apply brakes in a timely manner.

Methods Section

50 participants will be chosen to perform this experiment, out of which, 25 will be male and 25 will be female. Their ages will vary from 25 to 55.

Materials

The experiment will take place in a foggy weather on a 15km section of a two-lane highway. The leading will be Toyota Corolla and the following vehicle will be Toyota Corona. All participants will be driving the same vehicle so as to avoid any possible variations in the results.

Expected Results

It is expected that the drivers will maintain the minimum distance in relation to their speed and the speed of the leading vehicle. Also, it is expected that the drivers will maintain a minimum safe distance so that they can apply brakes in a timely manner. This is because it is believed that majority of the drivers are capable of recognizing directly and imitating a minimum safe distance in relation to time and density of the traffic.

However, it can be assumed that the drivers may show collective variations in relation to the minimum safe distance achieved and the time taken to achieve it. This is because the "traffic density," driving attitude and "depth perception" of the all the drivers is not the same.