Please cite this article in press as: Mendonc ¸ a, C., et al., Noise abatement and traffic safety: The trade-off of quieter engines and pavements on vehicle detection. Accid. Anal. Prev. (2012), http://dx.doi.org/10.1016/j.aap.2012.10.018 ARTICLE IN PRESS G Model AAP 2932 1–7 Accident Analysis and Prevention xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Accident Analysis and Prevention j ourna l h o mepage: www.elsevier.com/locate/aap Noise abatement and traffic safety: The trade-off of quieter engines and pavements on vehicle detection 1 2 C. Mendonc ¸ a a,d,* , E. Freitas b , J.P. Ferreira b , I.D. Raimundo b , J.A. Santos a,c,d Q1 3 a School of Psychology, Department of Basic Psychology, University of Minho, Portugal 4 b School of Engineering, Department of Civil Engineering, University of Minho, Portugal 5 c Centro Algoritmi, University of Minho, Portugal 6 d Centro de Computac ¸ ão Gráfica, Portugal 7 8 a r t i c l e i n f o 9 10 Article history: 11 Received 19 June 2012 12 Received in revised form 8 September 2012 13 Accepted 26 October 2012 14 15 Keywords: 16 Signal detection 17 Road traffic safety 18 Noise 19 Vehicles 20 Dense asphalt 21 Open asphalt rubber 22 Cobble stones 23 Psychoacoustic analysis 24 a b s t r a c t Road traffic sounds are a major source of noise pollution in urban areas. But recent developments such as low noise pavements and hybrid/electric engine vehicles cast an optimistic outlook over such an environ- mental problem. However, it can be argued that engine, tire, and road noise could be relevant sources of information to avoid road traffic conflicts and accidents. In this paper, we analyze the potential trade-offs of traffic-noise abatement approaches in an experimental study, focusing for the first time on the impact and interaction of relevant factors such as pavement type, vehicle type, listener’s age, and background noise, on vehicle detection levels. Results reveal that vehicle and pavement type significantly affect vehi- cle detection. Age is a significant factor, as both younger and older people exhibit lower detection levels of incoming vehicles. Low noise pavements combined with all-electric and hybrid vehicles might pose a severe threat to the safety of vulnerable road users. All factors interact simultaneously, and vehicle detection is best predicted by the loudness signal-to-noise ratio. © 2012 Published by Elsevier Ltd. 1. Introduction 25 Traffic related noise is nowadays the major source of environ- 26 mental noise in most industrialized nations and developing regions. 27 Its negative impact has been demonstrated at several instances, 28 from health to school efficiency and overall emotional annoyance 29 (e.g., Gorai and Pal, 2006; Passchier-Vermeer and Passchier, 2000; 30 Sanz et al., 1993; Freitas et al., 2012). It is therefore a matter of active 31 concern for traffic-related researchers, public authorities in health 32 and traffic, as well as transportation and road industries, to find 33 quieter alternatives to the major sources of transportation noise. 34 In a near future, we might expect a reduction of road traffic noise 35 both by pavements that are more efficient and because of the grow- 36 ing popularity of hybrid and all-electric vehicles. Therefore, there 37 is an optimistic outlook on health improvement and annoyance 38 reduction due to a quieter road traffic environment, specifically for 39 populations living in urban areas. 40 However, in urban areas traffic noise could also be a key fac- 41 tor for the awareness of imminent conflicts by vulnerable road 42 users. In other words, road, tire and engine noises might be used 43 * Corresponding author at: Centro de Computac ¸ ão Gráfica, Campus de Azurém, 4800-058 Guimarães, Portugal. Tel.: +351 253 510 580; fax: +351 253 510 581. E-mail address: catarina.mendonca@ccg.pt (C. Mendonc ¸ a). as meaningful signals by pedestrians and bicyclists: they can act as 44 attentional triggers, allowing for a better perception of speed and 45 proximity of incoming traffic and for timely reactions to avoid con- 46 flicts. Therefore, due to traffic noise abatement, we might face in 47 the near future an increasing trade-off between the improvement 48 of population’s health and the rise of accidents involving vulnera- 49 ble road users. Such trade-off analysis has never been approached 50 from an experimental perspective. 51 When compared to internal combustion vehicles, elec- 52 tric/hybrid engine vehicles have higher incidence of crashes 53 involving pedestrians and bicyclists (Garay-Vega et al., 2010; 54 Hanna, 2009). On the one hand road users show substantial interest 55 in driving quiet hybrid or all-electric cars; but on the other hand 56 they are concerned with the reduced conspicuity of such vehicles 57 (Wolgater et al., 2001). Some experimental studies have addressed 58 this issue. Ashmead et al. (2012) analyzed the path identification 59 of electric engine and internal combustion engine vehicles in quiet 60 and noisy environments. They found that in quiet environments 61 there were timely path identifications of the electrical vehicles, 62 but not in noisy ones. They also found that these judgments were 63 based on sound level, the main characteristic that is altered in elec- 64 tric/hybrid cars. Studies with visually impaired populations have 65 also revealed lower vehicle detectability of hybrid and all-electric 66 vehicles (Emerson et al., 2010). All these data have contributed to 67 the official recognition by the U.S. National Highway Traffic Safety 68 0001-4575/$ – see front matter © 2012 Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.aap.2012.10.018