Heavy Goods Vehicles Research Articles

Measuring the Motion of Vulnerable Road Users Relative to Moving HGVs

This paper focuses on measuring the motion of a cyclist moving adjacent to a heavy goods vehicle (HGV), from the detections of ultrasonic sensors installed along the side of the vehicle. The measurements are used in a prototype collision avoidance system that predicts the future relative motion and assesses the likelihood of a collision. An array of ultrasonic sensors is adopted to cover the near side of the HGV, where most of fatal collisions with cyclists occur. A method combining quadratic programming and Kalman filtering is developed in this paper for recovering the bearing angles of the cyclist from the detected distances provided by off-the-shelf ultrasonic sensors. The algorithms are developed for use in real time and practical constraints are considered. The simulation and testing results prove the effectiveness of the proposed method for a reasonable range of the speed differential between the cyclist and the HGV.

Dynamic Traffic Flow Entropy Calculation Based on Vehicle Spacing

In information theory, entropy is a measure of uncertainty. The higher the degree of chaos in a system, the higher its entropy. The concept of entropy has also been applied to the evaluation of transportation systems. Because of the limitation of the existing traffic information collection technology, an entropy-based evaluation method has not been widely applied. With the development of on-board sensors and the Internet of vehicles, vehicle spacing information will be easier to acquire and transmit in real time; furthermore, traffic flow entropy will be calculated in real time. Based on the vehicle spacing on the road, the proportion of the distance between the vehicles was taken as the input data of the entropy calculation, and the summation result was normalised and corrected to obtain the calculation corresponding to the entropy and the degree of disorder. On this basis, the entropy values at different moments were repeatedly calculated, and the dynamic traffic flow entropy on the road segment was summarised. We constructed a one-lane road segment model in the simulation software, recorded the vehicle information, and calculated the dynamic traffic flow entropy. A comparison of the difference in the traffic flow entropy between different proportions of heavy goods vehicles revealed that a large proportion of the heavy goods vehicles corresponded to a large traffic flow entropy, indicating a large degree of disorder. The simulation results showed that the proposed method has good scientific value and is practical.

Vibration serviceability assessment of GFRP pedestrian bridges

Over the past few decades, fibre-reinforced polymer (FRP) materials in general and glass-fibre-reinforced polymer (GFRP) in particular have become popular and competitive solutions in the construction of bridge objects. Because of their properties – such as high strength to weight ratios, ease of structure assembly, non-conductivity and chemical resistance – significant applications of the composite materials have been realised in the construction of footbridges in particular. In this paper, a numerical evaluation of the serviceability behaviour of two examples of composite material footbridges is presented. For the purpose of the study, it was assumed that the footbridges were made of the same composite material but they differ from each other with regard to structural geometry. The first stage of the study was the numerical estimation of the modal characteristics of the footbridges, i.e. their mode shapes and natural frequencies. The risk of the resonance phenomenon caused by pedestrian loading was then considered for both structures. In the next step of the calculations, the authors assessed the dynamic response of the footbridges to typical traffic loads; these types of load are transmitted to the structure through the ground and foundations. For numerical analysis, finite element (FE) models of the footbridges were prepared in the ABAQUS/Standard software program. The calculations included the representative time histories of the passage of a heavy goods vehicle and trains. Finally, the vibration comfort criteria for both footbridges were checked. The obtained results show that the comfort criteria are fulfilled.

Driver behaviour and crash involvement among professional taxi and truck drivers: Light passenger cars versus heavy goods vehicles

Professional drivers are drivers whose profession is to drive a vehicle such as truck and taxi for working purposes. However, these drivers constitute a heterogeneous group and generalizing assumptions about risky driving behaviour across the entire group might be misleading. The current study aimed to investigate similarities and differences of self-reported risky driving behaviour and crash involvement among different groups of professional drivers. Two rather large samples of taxi drivers obtained from 20 taxi stations in two cities (n = 381) and heavy goods vehicles (truck) drivers obtained from a roadside survey in 10 provinces (n = 785) completed the same 27-item Driver Behaviour Questionnaire (DBQ) in Iran. Principal component analysis showed that the DBQ segmented into four dimensions both among taxi and truck drivers. Further, a multi-group confirmatory factor analysis (MGCFA) supported strong measurement invariance in the DBQ factor structure across the two samples. The results showed that taxi drivers were more likely than truck drivers to commit errors as well as ordinary and aggressive violations. A one unit increase in ordinary and aggressive violations increased the probability of having experienced a traffic crash in the last year by 69% and 98% for taxi drivers, respectively, and 37% and 42% among truck drivers, respectively. This highlights that driving violations increased the probability of crash involvement almost twice as much among taxi drivers compared to truck drivers. Policymakers could target ordinary and aggressive violations by establishing better driving training and by improving the licensing procedures among professional drivers.

The role of ports in reduction of road transport pollution in port cities

Abstract Despite numerous actions taken by port authorities to enable modal shift, road transport has been playing a dominating role in serving the hinterland of many ports. Millions of tonnes of cargoes are carried by heavy goods vehicles which due to the location of ports within conurbations have to join urban traffic. Freight traffic generates considerable external costs caused by congestion, accidents, noise or pollutant emissions. This article is aimed at identification and classification of the tools applied by port authorities in order to limit exhaust emissions and congestion caused by heavy goods vehicles handled in ports.

Grenzverkehr als ein Maß für grenzüberschreitende Beziehungen

Intensity and structure of cross-border traffic are influenced by economic, social, political,formal-legal, infrastructural, environmental, and even historical factors. A part ofthese factors result from global processes, which may lead to dramatic transformationshaving very broad repercussions. The present article tracks the influence exerted by selectedeconomic and geopolitical events on traffic across the eastern border of Poland.These events include the accession of Poland to the EU and to the Schengen Zone, theRussian-Ukrainian conflict, and the introduction of embargoes on definite groups of goodsby Russia. The characteristics of cross-border traffic are treated, therefore, as representinga measure for the resilience displayed by the trans-border system of socio-economicconnections. Cross-border traffic is analysed by traffic of persons and heavy goods vehicles(HGV). It is demonstrated that cargo traffic is subjected to the geopolitical andmacro-economic situation, while sizes and directions of the traffic of persons are mainlyshaped by legal and local cross-border trade conditions.

Monitoring and analysis of the operational environment in an extra-long highway tunnel with longitudinal ventilation

Owing to their ability to dilute pollutant concentrations and enhance visibility, which significantly improves driving safety, ventilation systems have become one of the critical subsidiary facilities in extra-long highway tunnels. The spatiotemporal distribution characteristics of toxic gases, visibility, and air velocity in the Qin Mountains No. 1 tunnel (uphill bore, 6.02 km) were analyzed by combining a traffic survey with an analysis of environmental monitoring data. The analysis indicated that CO and visibility are unsuitable as primary control indexes for mountain tunnel ventilation when heavy goods vehicles (HGVs) represent a fairly large proportion of the traffic composition. The maximum in-tunnel NO2 concentration was 2.3 ppm, which is 2.3 times the design standard. Differences in the NO2/NOx ratio proved that gaps still exist between the diesel vehicle exhaust gas after-treatment technologies used in China and Europe. Consequently, stricter diesel exhaust emission standards and more intelligent ventilation-control technologies should be adopted in future tunnel designs. The results not only offer data that support the establishment of in-tunnel air quality control standards but also provide a feasible method for predicting the levels of various pollutants and developing ventilation-control strategies.

Simulation Analyses of Two On-Ramp Lane Arrangements

Ramps are vital pieces of infrastructure connecting city traffic networks to freeways. The performance of a ramp is to some extent determined by the on-ramp lane arrangement. In this paper, our primary aim is to evaluate the performance in terms of travel time and vehicle emissions for two on-ramp lane arrangements: added lane and zip merging. We estimate the travel time and CO2 emissions on the basis of the speed, and acceleration of vehicles in accordance with the improved comprehensive modal emission model (CMEM), and then analyse the impacts of traffic volume and heavy goods vehicles (HGVs) on travel time and emissions. The impacts of main road traffic flow on travel time and emissions for the two on-ramp lane arrangements are analysed under scenarios with traffic volumes of 800, 1 000, 1 200, 1 400, 1 600 and 1 800 vehs/h/lane. Meanwhile, the relationships between travel time, emissions and various proportions of HGVs (2%, 4%, 6%, 8% and 10%) for both on-ramp lane arrangements are evaluated as well. We eventually present emission contour charts for the two on-ramp lane arrangements based on the possible combinations of traffic volumes and HGV percentages.

Effect of Traffic and Geometric Characteristics of Rural Two Lane Roads on Traffic Safety: a case study of Ilesha-Akure-Owo road, South-West, Nigeria

Road safety engineering involves identifying influencing factors causing traffic crashes through accident data, carrying out detailed accident studies at different locations and implementing relevant remedial measures. This study was carried out to establish relationship between traffic accident characteristics (frequency and severity) and traffic and road design characteristics on a two-lane highway. Statistical models applied in traffic accident modeling are Poisson regression, Negative Binomial regression (NB), and Zero-Inflated Negative Binomial regression (ZINB).; Traffic flow and road geometry related variables were the independent variables of the models. Using Ilesha-Akure-Owo highway, South-West, Nigeria accident prediction models were developed on the basis of accident data obtained from Federal Road Safety Commission (FRSC) during a 4-year monitoring period extending between 2012 and 2015. Curve radius (CR), lane width (LW), shoulder factor (SF), access road (CHAR), average annual daily traffic (AADT), parentage heavy good vehicle (HGV) and traffic sign posted (TSP) were the identified effective factors on crash occurrence probability. Finally, a comparison of the three models developed proved the efficiency of ZINB models against traditional Poisson and NB models. Keywords— Traffic accidents. Single carriageway, accident prediction model, road geometric characteristics.

Analysing the heavy goods vehicle “écotaxe” in France: Why did a promising idea fail in implementation?

In October 2014, France abandoned the implementation of the écotaxe, a major country-wide Electronic Tolling System (ETS) designed to charge for the use of national and local roads, which were not covered by the traditional toll system. The écotaxe originated from a political consensus and was designed with the collaboration of business stakeholders. However, unforeseen implementation difficulties resulted in a renouncement at a late stage, when the infrastructure was already deployed. According to a recent report from the French body in charge of auditing public expenses, it generated a cost of 953 million euros. In analysing what happened during the policy delivery stage, this paper provides insights to policymakers in countries where ETS is envisaged.The ETS system was piloted in summer 2013, and the “go live” date was 1st September 2014. Data was collected ‘live’, in March 2014, featuring 21 interviews, with the aim of better understanding the expected challenges and impacts on the business stakeholders. At the time, stakeholders accepted that the project would go ahead: while further implementation challenges remained, few anticipated them to fully derail the project within 6 months. Retrospective analysis of the data collected in March 2014 can help to deepen policymakers’ insights into why the project ultimately failed and better understand the main lessons to be learnt. The findings show that the écotaxe, presented as environmental taxation by policymakers, had been in reality perceived and accepted by business stakeholders as more of an infrastructure tax. Interestingly, this in itself does not explain the failure. The main explanation is to be found in the perceived inequities associated with the charging approach, excluding privately-operated motorways, and the failure of the ad valorem surcharging system designed as a means of passing the tax costs to shippers. These findings should be valuable for policymakers anywhere the introduction of a similar ETS system is being contemplated.

Factors Influencing the Design Life of Old Steel Bridges

When deciding about the specific design life for bridge structures, care should be taken to ensure that the structure fulfils all the fundamental requirements of structural reliability in terms of robustness, safety and serviceability in order to achieve the service life of the bridge. Load and material properties, cross-section and system geometry are the basic variables or parameters that are being used when considering the design life of bridge structures. The design life of bridge structures as specified in the Eurocodes and British Standards is 100 and 120 years respectively while in AASHTO-LRFD it is for 75 years. However, in all these codes of practice, there are no specifications or provision or guidelines related to sustaining the service life of bridge structures (Bartholomew, 2007 & 2009). This is because the service life depends on the durability of the structure which is heavily influenced by several factors such as fatigue, corrosion and changes in superimposed loads. Therefore, with an increase in traffic loading together with climate changes, the demand to ensure service life is very acute because of the importance of bridge structures in the infrastructure network, which is especially true for long span bridges. Also, with different load applications of heavy good vehicles (HGVs) occurring during the design life, this will affect the structural integrity of old steel bridges. For example, old bridges in many countries including Malaysia were designed using British Standard compliances. Since the Eurocodes have been widely practising nowadays, the estimation of loading applied might be different with the old code of practice. Plus, with the traffic increasing every year without any control, the maintenance for the old bridges especially should be more frequent as these bridges may not have benefited to the remedial measures to improve the fatigue performances. Therefore, the actual service life may not reach the expected service life as the actual service life depends on the exposure condition of the structure, quality of materials, design and construction and also the level of maintenance performance. In addition, with the increase in traffic load and frequency, this could seriously jeopardise the integrity of old bridges to meet their actual service life. This paper discusses the issue concerning the design and remaining service life estimation used when designing and appraising steel bridges.

Camera-based measurement of cyclist motion

Heavy goods vehicles are overrepresented in cyclist fatality statistics in the United Kingdom relative to their proportion of total traffic volume. In particular, the statistics highlight a problem for vehicles turning left across the path of a cyclist on their inside. In this article, we present a camera-based system to detect and track cyclists in the blind spot. The system uses boosted classifiers and geometric constraints to detect cyclist wheels, and Canny edge detection to locate the ground contact point. The locations of these points are mapped into physical coordinates using a calibration system based on the ground plane. A Kalman Filter is used to track and predict the future motion of the cyclist. Full-scale tests were conducted using a construction vehicle fitted with two cameras, and the results compared with measurements from an ultrasonic-sensor system. Errors were comparable to the ultrasonic system, with average error standard deviation of 4.3 cm when the cyclist was 1.5 m from the heavy goods vehicles, and 7.1 cm at a distance of 1 m. When results were compared to manually extracted cyclist position data, errors were less than 4 cm at separations of 1.5 and 1 m. Compared to the ultrasonic system, the camera system requires simple hardware and can easily differentiate cyclists from stationary or moving background objects such as parked cars or roadside furniture. However, the cameras suffer from reduced robustness and accuracy at close range and cannot operate in low-light conditions.

A strategy for avoiding collisions between heavy goods vehicles and cyclists

Heavy goods vehicles turning left across the path of a cyclist cause approximately 40% of the most serious injuries and fatalities to cyclists. A collision avoidance strategy is proposed in this study. Based on measurement of the current position and motion of the cyclist relative to the heavy goods vehicle, the future position of the cyclist after a short period is predicted by assuming constant acceleration and constant yaw rate. The brakes on the heavy goods vehicle are applied if the predicted future cyclist position overlaps the future envelope of the heavy goods vehicle. A parametric study shows that a high portion of potential collisions could be prevented in this way. Nineteen fatal accidents involving left-turning heavy goods vehicles and cyclists are reconstructed in simulation from police report files and the collision avoidance system is simulated. It is concluded that the introduction of the proposed collision avoidance strategy could possibly have prevented up to 18 of the 19 deaths in these accidents.

Development of a Heavy Containment Level Bridge Rail for Istanbul

Abstract The international highways within the city limits of Istanbul are used to transit more than 15 million trucks and other heavy good vehicles per year. According to the statistics, the number of single truck run of the road accidents is in the rise. Recent accidents on bridges showed that currently used bridge rails specified by Istanbul Metropolitan Municipality (IMM) lack the required design criteria to safely contain and redirect heavy vehicles. The objective of this study is therefore design, analyze and test a new high containment level (HCL) bridge rail to be used on bridges on high risk locations, within the city limits of Istanbul. After the development and simulation phases, the bridge rail is subjected to full-scale crash testing in accordance with European Standard EN1317 to conclusively prove its adequacy. This study is of importance since the barrier is the first nationally developed high containment level bridge rail in Turkey. The bridge rail, YIM04 is currently in use on several bridge decks in Istanbul.

A heavy goods vehicle fleet forecast for South Africa

Purpose: To develop and apply a methodology to calculate the heavy goods vehicle fleet required to meet South Africa’s projected road freight transport demand within the context of total surface freight transport demand.Methodology: Total freight flows are projected through the gravity modelling of a geographically disaggregated input–output model. Three modal shift scenarios, defined over a 15-year forecast period, combined with road efficiency improvements, inform the heavy goods vehicle fleet for different vehicle types to serve the estimated future road freight transport demand.Findings: The largest portion of South Africa’s high and growing transport demand will remain on long-distance road corridors. The impact can be moderated through the concurrent introduction of domestic intermodal solutions, performance-based standards in road freight transport and improved vehicle utilisation. This presupposes the prioritisation of collaborative initiatives between government, freight owners and logistics service providers.Research limitations: (1) The impact of short-distance urban movements on fleet numbers is not included yet. (2) Seasonality, which negatively influences bi-directional flows, is not taken into account owing to the annual nature of the macroeconomic data. (3) The methodology can be applied to other countries; the input data are however country-specific and findings can therefore not be generalised. (4) The future possibility of a reduction in absolute transport demand through, for example, reshoring have not been modelled yet.Practical implications: Provides impetus for the implementation of domestic intermodal solutions and road freight performance-based standards to mitigate the impact of growing freight transport demand.Societal implications: More efficient freight transport solutions will reduce national logistics costs and freight-related externalities.Originality: Develops a methodology for forecasting the heavy goods vehicle fleet within the context of total freight transport to inform government policy and industry actions.

DRIVER’S CAR FOLLOWING HEADWAY ON SINGLE CARRIAGEWAY ROADS

One of many aspects that are considered to influence road crashes and road traffic handling capacity is the drivers’ car following behaviour. This study examines the distance separation between impeded vehicles on single carriageway roads. Data defining headway and speed for more than 8000 vehicles were collected using video cameras to record traffic movement at four sites in Malaysia. The distance headways and associated vehicle speeds were separated into vehicle following category by vehicle type and then into speed classes for vehicle following vehicle: car following car, car following heavy goods vehicle (HGV), HGV following HGV and HGV following car categories. In most cases the lognormal distribution was found to be an appropriate representation of the variation in distance headways for vehicles within a particular speed class. Linear regression models were developed to represent the relationships between distance headway and speed and the predicted variation in population mean distance headway with vehicle speed. In general, Malaysian drivers tend to follow another vehicle closely and platoons appeared to develop rapidly.

Assessing rear-end crash potential in urban locations based on vehicle-by-vehicle interactions, geometric characteristics and operational conditions

Rear-end crashes are one of the most frequently occurring crash types, especially in urban networks. An understanding of the contributing factors and their significant association with rear-end crashes is of practical importance and will help in the development of effective countermeasures. The objective of this study is to assess rear-end crash potential at a microscopic level in an urban environment, by investigating vehicle-by-vehicle interactions. To do so, several traffic parameters at the individual vehicle level have been taken into consideration, for capturing car-following characteristics and vehicle interactions, and to investigate their effect on potential rear-end crashes. In this study rear-end crash potential was estimated based on stopping distance between two consecutive vehicles, and four rear-end crash potential cases were developed. The results indicated that 66.4% of the observations were estimated as rear-end crash potentials. It was also shown that rear-end crash potential was presented when traffic flow and speed standard deviation were higher. Also, locational characteristics such as lane of travel and location in the network were found to affect drivers’ car following decisions and additionally, it was shown that speeds were lower and headways higher when Heavy Goods Vehicles lead. Finally, a model-based behavioral analysis based on Multinomial Logit regression was conducted to systematically identify the statistically significant variables in explaining rear-end risk potential. The modeling results highlighted the significance of the explanatory variables associated with rear-end crash potential, however it was shown that their effect varied among different model configurations. The outcome of the results can be of significant value for several purposes, such as real-time monitoring of risk potential, allocating enforcement units in urban networks and designing targeted proactive safety policies.

A Criteria-Based Approach to Evaluating Road User Charging Systems

A set of important criteria to consider when evaluating potential road user charging system (RUCS) are identified. These criteria are grouped into five categories: charging precision, system costs & societal benefits, flexibility & modifiability, operational aspects, and security & privacy. The criteria are then used in a comparative analysis of five RUCS candidates for heavy goods vehicles. Two solutions are position-based systems and one is based on tachographs. The two remaining solutions are based on fuel taxes. For each of the solutions we estimate how well it fulfils each of the criteria. One way of making general comparisons of the approaches is to give each of the criteria a specific weight corresponding to how important it is. We show that these weights heavily influence the outcome of the comparison. We conclude by pointing out a number of important issues needing attention in the process of developing RUCS.

Modelling the Performance of Signalized Intersections Near Railway Crossings

Railway related pre-emption time, which refers to the time needed to clear a vehicle from the pathway of a train, isa necessary input for appropriate pre-emption traffic signal settings. It is, however, usually left to the judgment of the signal engineer, using assumptions not always based on hard evidence. The research reported here analysed the safety and performance at railway crossings in the vicinity of signalized intersections with the aid of micro traffic simulation modelling. The developed model was calibrated by comparing the time that the last vehicle on the railway tracks to be cleared. A location in Brisbane, Australia, was chosen to apply the proposed methodology. The case study was used to evaluate three settings, which were implemented using fixed signal time; pre-emption with actuated signal; and actuated signal only. The signal logic was developed with the aid of an external signal controller to replicate pre-emption technology. The resultsfrom the simulation model show that the use of the pre-emption benefits safety and driving performance by changing signals dynamically in accordance withconditions related to traffic flow, train frequency and the proportion of heavy goods vehicles.

Comparison of results from large-scale and small-scale tunnel experiments

A series of 1:20 small-scale tunnel experiments have been carried out as a scaled down representation of a previously undertaken large-scale heavy goods vehicle (HGV) cargo load tunnel fire experiment. The small-scale tunnel has dimensions of 0.365 m (W) × 0.260 m (H) × 11.9 m (L) and a maximum forced ventilation velocity of 0.68 m/s is adopted corresponding to the velocity of 3 m/s used at large-scale. A gas burner and cribs constructed of medium density fireboard (MDF) have been used as the fuel sources with temperatures, heat release rate (HRR) and velocity data recorded in the small-scale tunnel experiments. A scaled down HRR curve derived from the large-scale experiment was reproduced by the gas burner. Temperatures in the small-scale gas burner experiment can effectively represent those at large-scale during the fire growth and decay stages although measurements at the fully developed stage are lower than the results from the large-scale tunnel experiment. In the small-scale tunnel experiments using the cribs time delays are applied to correct the recorded data in order to obtain the instantaneous HRR. Temperature profile comparisons between the small-scale crib and large-scale HGV cargo load experiments are not applicable since the HRR curves from the crib experiments only approximately reproduce the large-scale HRR profile.