Experimental research on the effectiveness of speed reduction markings based on driving simulation: A case study

Highlights

• We tested the effectiveness of speed reduction markings (SRMs).

• We did an empirical research based on a driving simulator.

• We used the analysis of variance (ANOVA) and the contrast analysis.

• Longitudinal speed reduction markings (LSRMs) would slightly influence subjects’ speed choice and maneuver, but such effects were not significant.

• Transverse speed reduction markings (TSRMs) could significantly influence subjects’ speed choice and maneuver.

Abstract

The objective of this paper is to test the effectiveness of speed reduction markings (SRMs). The empirical data including vehicle operations and drivers’ psychological and physical reactions were collected in a driving simulator. An index—the relative speed difference—was developed to evaluate the effectiveness of speed reduction markings. Researchers analyzed data to test the effectiveness of speed reduction markings and quantitatively study their effects and the deceleration process. Out of 15 subjects, there were 1 (7%), 2 (13%), and 7 (47%) subjects who decelerated while driving through the downhill section in the No SRMs scenario, Longitudinal SRMs scenario and Transverse SRMs scenario, respectively. In terms of speed and subjects’ decelerating maneuver, the results of the analysis of variance (ANOVA) and the contrast analysis (S–N–K method) showed that transverse speed reduction markings (TSRMs) could significantly influence subjects’ speed choice and maneuver (P < 0.05).

Introduction

With the growth of the national economy and the improvement of the Chinese people's standard of living, the number of vehicles has increased rapidly in recent years. Data from official reports indicated that there were 125 million registered vehicles in China in 2006, and this number has reached 191 million in 2010 (National Bureau of Statistics of China, 2011). In the meantime, traffic crashes in China have contributed to a staggering amount of property damage as well as numerous deaths. According to an official report in China, in 2010 police reported 39,060,164 traffic crashes, resulting in 65,225 fatalities and 254,075 injuries and causing a direct economic loss of about ¥930 million (Road Traffic Crashes of China, 2011). Speeding, drunk driving and driver fatigue were the three main factors leading to traffic crashes; speeding alone was responsible for 14.2 percent of all traffic fatalities in 2010 (Zheng, 2007). Therefore, to better address this issue, installing speed control devices at sites with greater possibility of speed-related traffic crashes is an important approach to reducing crashes and improving road safety.

In China, speed control devices are classified into three categories: non-intrusive speed control devices, including automatic speed enforcement, speed limit signs and speed reduction marking; less intrusive speed control devices, such as thermoplastic vibration speed reduction markings; and intrusive speed control devices, including spikes, cement speed bumps, pavement groove strips and rubber speed bumps. Non-intrusive speed control devices, especially speed reduction markings (SRMs), have been used extensively on highways and urban expressways in China.

According to the Chinese national standard Road Traffic Signs and Markings, SRMs are used to warn drivers of the need to reduce their speed (Standardization Administration of the People's Republic of China, 2009). SRMs are placed on or in advance of horizontal or vertical curves, tunnels, or other featured roads where drivers need to slow down in advance. SRMs include longitudinal speed reduction markings (LSRMs) and transverse speed reduction markings (TSRMs); both can be audible and vibratory (Standardization Administration of the People's Republic of China, 2009). The patterns of SRMs were shown in Fig. 1(a) and (b). The national standard describes detailed design requirements, including the size, length, width, spacing, as well as the placement location. However, there is relatively little research on the effectiveness of speed reduction markings on speed control in China and the current practices in their design and management operations may not be economical. In addition, SRMs used in other countries often differ in their design patterns as well as placement, and research results from other countries may not be applicable in China. Thus, this research project investigated the effectiveness of SRMs in order to better improve their application in China.