Use of speed profile as surrogate measure: Effect of traffic calming devices on crosstown road safety performance

Urban road safety management is usually characterized by the lack of sufficient, good quality crash data and low budgets to obtain it even though many traffic accidents occur there. For example, 54 percent of road crashes in Spain take place in urban areas, and 10 percent of urban fatal crashes occur on crosstown roads, which are rural roads that traverse small communities. Traffic calming measures (TCMs) are often implemented on these parts of rural roads that traverse small communities in order to reduce both the frequency and severity of crashes by lowering speeds, but evaluation of their effectiveness has been limited. The objective of this study was to develop a methodology using continuous speed profiles to evaluate the safety effectiveness of TCMs on crosstown roads as part of an integrated system in the absence of historical data. Given the strong relationship between speed and crash experience, safety performance can be related to speed. Consequently, speed can be used indirectly as a surrogate safety measure in the absence of crash and speed data. Two indexes were defined in this study as surrogate safety measures based on the continuous speed profile: Ra and Ea. Ra represents the absolute accumulated speed variations relative to the average speed and is inversely related to accumulated speed uniformity; and Ea represents the accumulated speed variations above the speed limit and is directly related to accumulated speeding. Naturalistic data were collected using GPS trackers for 12 scenarios with different TCM spacings. Then, the indexes were applied to individual observed speed profiles (individual analysis) as well as the operating speed profile (global analysis). The values obtained from individual and global analysis were statistically different. Spacing lower than 110 m, which was found optimal from previous research, did not allow drivers to modify their speeds as the accumulated speed uniformity was quite similar regardless of the average operating speed; and, accumulated speeding was also minimized. Consequently, the scenarios where the TCMs were implemented according to the technical criteria presented a better design quality. On the other hand, age and gender differences did not seem to affect the average speeds or the accumulated speed uniformity and accumulated speeding.Moreno Chou, AT.; García García, A. (2013). Use of speed profile as surrogate measure: Effect of traffic calming devices on crosstown road safety performance. Accident Analysis and Prevention. 61:23-32. doi:10.1016/j.aap.2012.10.013S23326

Motorcycle safety after-dark : the factors associated with greater risk of road-traffic collisions

The effect of ambient light level on road traffic collisions (RTCs) involving a motorcycle was investigated. Data were drawn from the STATS19 database of UK reported RTCs for the period 2005–2015. To isolate the effect of ambient light (daylight vs darkness) an odds ratio was used to compare RTCs at specific times of day in the weeks either side of the Spring and Autumn clock changes. This work extended previous studies by using a more precise method for distinguishing between RTCs in daylight and after dark, thus avoiding the ambiguity of twilight. Data for four-wheel motor vehicle (FWMV) RTCs were also investigated to provide a datum. As expected, the risk of an RTC occurring was significantly higher after dark compared to daylight for both motorcycles and FWMVs. Investigation of contextual factors suggests that risk after dark is significantly higher for motorcycles compared to FWMVs for RTCs with two-vehicles, on roads with low speed limits (≤30 mph), at T-junctions, and junctions controlled by a give way sign. These are the situations where visual aids for increasing conspicuity after dark have the greater potential for reducing motorcycle RTCs

Airports and ageing passengers: A study of the UK

Globally, improved standards of living, nutrition and medical treatment are extending human life expectancy and enhancing quality of life with the result that an increasing number of ageing passengers are using airports. This ‘grey boom’ presents both challenges and opportunities for airports as older travellers exhibit distinct and different travel characteristics concerning their propensity to fly, their travel purpose, trip duration, destination, surface access preferences, dwell time, retail habits, familiarity with airport automation and self-service technologies, and use of terminal facilities such as airport information desks, adaptive and assistive technologies and special assistance support. The aim of this paper is to use publicly available data to undertake an exploratory investigation into the use of UK airports by older travellers and make recommendations for future policy and practice. Overall, the study finds that the impact of this observed demographic change varies by individual airport and thus future policy and management of an ageing passenger profile needs to reflect the operational challenges on a location-by-location basis

Quantifying the effect of landscape structure on transport costs for biorefinery of agricultural and forestry wastes in Malaysia

In the context of climate change, sustainable biorefinery helps to mitigate carbon emissions. This paper examines how landscape structure metrics allow us to better understand the economics of agricultural and forestry wastes transportation. To verify that the landscape structure plays a significant role, we quantify the fragmentation of various lignocellulosic feedstock in Malaysia, as a typical tropical country. Fragmentation is compared with the variations of truck size, transport distance, and biomass nature. We use GRASS GIS to develop a series of transport cost maps, to quantify feedstocks, to run various biomass transport simulations, optimize locations of potential biorefineries, and to compute landscape structure metrics. We find that the cost of 1 million tonnes feedstock increases by more than 4 USD/tonne for every added unit of edge density (fragmentation index). It also increases by more than 6 USD/tonne for every added 100 km of average transportation. The average truck size has also a strong nonlinear relation to the cost with −84 USD/tonne when changing from 3‐ to 26‐tonne trucks. To our knowledge, this is the first paper to address simultaneously fragmentation with the other classical logistic factors in a tropical country like Malaysia. It has strong implications for policymakers: the importance of the landscape structure makes a seemingly abundant biomass not viable for biorefineries if too fragmented compared to a much less abundant one, but more concentrated. It also implies that in tropical countries where the landscape is typically very fragmented, multi‐crop feedstocks could be considered for sustainable biorefineries

Environmental noise exposure, early biological risk and mental health in nine to ten year old children: a cross-sectional field study

<p>Abstract</p> <p>Background</p> <p>Previous research suggests that children born prematurely or with a low birth weight are more vulnerable to the mental health effects of ambient neighbourhood noise; predominantly road and rail noise, at home. This study used data from the Road Traffic and Aircraft Noise Exposure and Children's Cognition and Health (RANCH) study to see if this finding extends to aircraft and road traffic noise at school.</p> <p>Methods</p> <p>Children and their parents from schools around three European airports were selected to represent a range of aircraft and road traffic noise exposure levels. Birth weight and gestation period were merged to create a dichotomous variable assessing 'early biological risk'. Mental health was assessed using the Strengths and Difficulties Questionnaire (SDQ). Complete data were available for 1900 primary school children.</p> <p>Results</p> <p>Children who were 'at risk' (i.e. low birth weight or premature birth) were rated as having more conduct problems and emotional symptoms and poorer overall mental health than children not at risk. However, there was no interaction between aircraft or road traffic noise exposure at school and early biological risk.</p> <p>Conclusions</p> <p>Data from the RANCH study suggests that children with early biological risk are not more vulnerable to the effects of aircraft or road traffic noise at school on mental health than children without this risk; however they are more likely to have mental ill-health.</p

Perceived integrated impact of visual intrusion and noise of motorways: Influential factors and impact indicators

Motorways are often seen as intrusive to both landscape and soundscape, and recent studies on multisensory perception suggest that an integrated assessment of the environmental impacts is necessary. This paper investigates the effects of traffic condition, distance to road and background landscape on the perceived integrated impact of noise and visual intrusion of motorways, and explores if noise exposure can be a powerful indicator for the perceived integrated impact. Six traffic conditions, consisting of three levels of noise emission × two levels of heavy good vehicle percentage in traffic composition, two types of background landscape and three distances to road, were designed as experimental scenarios, and created using computer visualisation and edited audio recordings. A laboratory experiment was carried out to obtain ratings of perceived environmental quality of each experimental scenario. The results show that traffic volume as expressed by noise emission level strongly influenced the perceived integrated impact, whereas traffic composition did not make noticeable differences. Distance to road was the second most influential factor, followed by background landscape. A regression model using noise level at receiver position and type of background landscape as independent variables was developed and can explain about a quarter of the variation in the perceived integrated impact

Is Governing Capacity Undermined? Policy Instruments in Smart Mobility Futures

The aim of this chapter is to analyse how the governing capacity of current policy instruments might be affected in futures of smart mobility. In order to explore this issue, the authors make use of the so-called NATO (nodality, authority, treasure, organisation) framework for analysing two contrasting scenarios. The analyses show that the overall governing capacity of many of the policy instruments is strengthened or maintained in both of the scenarios. However, the governing capacity of some policy instruments is reduced, and some seem to need calibration, not least because authorities’ access to and control over data are under question. Future governing capacity hinges on access to data, although all resources are, in one way or another, affected

Trafiksäkerhetsenkäten 2011

This is the 30th study in a series of annual surveys on road safety conducted since 1981. The study is conducted by Statistics Sweden on behalf of the the Swedish Transport Administration and aims to identify and analyse traffic safety statistics. The study is is done by a questionnaire directed to a stratified sample of the population. The study from 2011 had a 53 percent response rate and a sample of 8 407 randomly selected people aged between 15 and 84 years. The questions in the study include, for example, traffic behaviour and traffic patterns; attitudes to road safety and traffic rules, the relation between alcohol and traffic and child safety in traffic. Both motor traffic, bicycle and foot traffic is concerned. A total of 33 questions are used, including descriptive questions, estimation questions and attitude questions. Purpose: The survey aims to identify and analyse traffic safety statistics.Detta är den 30:e studien i en serie av årliga undersökningar om trafiksäkerhet som genomförts sedan 1981. 2011 års studie har har utförts av Statistiska centralbyrån på uppdrag av Trafikverket och syftar till att ta fram och analysera trafiksäkerhetsstatistik. Undersökningen genomförs genom ett frågeformulär riktad till ett stratifierat urval av Sveriges befolkning. Förutom den pappersenkät som användes fanns också möjlighet att besvara frågeformuläret på webben. Svarsfrekvensen var 53 procent för urvalet 8 407 slumpmässigt utvalda personer i åldrarna 15 till 84 år. Frågorna i studien behandlar bland annat trafikbeteende och trafikvanor, både hos sig själv och andra, inställning till trafiksäkerhet och trafikregler, relationen mellan alkohol och trafik samt barns säkerhet i trafiken. Både motortrafik, cykel och gångtrafik berörs. Totalt används 33 stycken frågor som består bland annat av beskrivande frågor, skattningsfrågor och attitydfrågor. Syfte: Syftet med studien är att ta fram och analysera trafiksäkerhetsstatistik