Four-lane Highway Research Articles

Comparison of results from road noise measurements and road noise calculation methods CNOSSOS-EU, Nord2000Road and Nord96

To gain more experience with CNOSSOS-EU a series of road noise measurements was conducted to compare actual measurements with calculated results. These measurements were taken along an urban four-lane motorway in Oslo with speed limit 70 km/h, during the summer of 2023, in accordance with Norwegian standard NS 8174-02 as far as practicable. The resulting road noise levels LAeq, 24t were compared to the calculated levels obtained using three different methods for road traffic: Nord96, Nord2000 and CNOSSOS-EU. The measurement locations were chosen to span from open areas to more complex situations. The key finding is that the calculated noise levels consistently exceed the measured levels across all three calculation methods. Interestingly, the discrepancies between measured and calculated levels are highest in open areas and tend to diminish in more complex scenarios. Specifically, Nord2000 yields higher levels than Nord96 and CNOSSOS-EU, although the differences between Nord2000 and the other two methods become negligible in complex situations. Additionally, the transition in software from Cadna/A to SoundPLAN influences the results. These findings indicate a need for further investigation into source data for vehicles, and potentially road surfaces.

Optimal setting of traffic prohibition and warning signs on four-lane highway in plain terrain based on driver's EEG signal

Optimal setting of traffic prohibition and warning signs on four-lane highway in plain terrain based on driver's EEG signal

Development of trust-based autonomous driving framework in New Zealand

PurposeAutonomous vehicles (AVs) have the potential to transform the infrastructure, mobility and social well-being paradigms in New Zealand (NZ) amid its unprecedented population and road safety challenges. But, public acceptance, co-evolution of regulations and AV technology based on interpersonal and institutional trust perspectives pose significant challenges. Previous theories and models need to be more comprehensive to address trust influencing autonomous driving (AD) factors in natural settings. Therefore, this study aims to find key AD factors corresponding to the chain of human-machine interaction (HMI) events happening in real time and formulate a guiding framework for the successful deployment of AVs in NZ.Design/methodology/approachThis study utilized a comprehensive literature review complemented by an AV users’ study with 15 participants. AV driving sprints were conducted on low, medium and high-density roads in Auckland, followed by 15 ideation workshops to gather data about the users’ observations, feelings and attitudes towards the AVs during HMI.FindingsThis research study determined nine essential trust-influencing AD determinants in HMI and legal readiness domains. These AD determinants were analyzed, corresponding to eight AV events in three phases. Subsequently, a guiding framework was developed based on these factors, i.e. human-machine interaction autonomous driving events relationship identification framework (HMI-ADERIF) for the deployment of AVs in New Zealand.Research limitations/implicationsThis study was conducted only in specific Auckland areas.Practical implicationsThis study is significant for advanced design research and provides valuable insights, guidelines and deployment pathways for designers, practitioners and regulators when developing HMI Systems for AD vehicles.Originality/valueThis study is the first-ever AV user study in New Zealand in live traffic conditions. This user study also claimed its novelty due to AV trials in congested and fast-moving traffic on the four-lane motorway in New Zealand. Previously, none of the studies conducted AV user study on SUV BMW vehicle and motorway in real-time traffic conditions; all operations were completely autonomous without any input from the driver. Thus, it explored the essential autonomous driving (AD) trust influencing variables in human factors and legal readiness domains. This research is also unique in identifying critical AD determinants that affect the user trust, acceptance and adoption of AVs in New Zealand by bridging the socio-technical gap with futuristic research insights.

Safety and Mobility Performance Comparison of Two-Plus-One and Two-Lane Two-Way Roads: A Simulation Study

Two-plus-one (2+1) highways are a special configuration of two-lane two-way (TLTW) highways with a continuous center lane that is used to alternate passing lanes. The main objective of this paper is, therefore, to evaluate the suitability of the 2+1 design for Middle East conditions as a replacement for traditional TLTW roads with higher traffic volumes or as an interim solution before transforming TLTW roads into four-lane highways. In our analysis, we considered both safety and mobility performances by comparing the 2+1 and TLTW designs. The new suggested 2+1 designs were evaluated, with the first design prohibiting overtaking in the opposite direction, while the second design permitted it. Additionally, two-speed-limit strategies, uniform speed limit (USL), and differential speed limit (DSL) were also evaluated. The results showed that the 2+1 design, which prohibited overtaking in the opposite direction, was superior to TLTW in terms of mobility and safety, while the other design compromised safety compared to TLTW. The results provide valuable information to policymakers, urban planners, and transport authorities to guide evidence-based decisions on the integration of the 2+1 design as a viable solution for sustainable and efficient transportation.

Optimal lane management policy for connected automated vehicles in mixed traffic flow

The management of lanes for mixed traffic flow consisting of connected automated vehicles (CAVs) and human-driven vehicles (HDVs) can effectively improve the operational efficiency of highways. This paper proposes an optimal lane management policy for connected automated vehicles in mixed traffic flow on highways. Firstly, the functioning characteristics of the mixed traffic flow are analyzed in three aspects, including car-following mode, headway, and platoon size. Secondly, the vehicle probability distributions under different lane management strategies are derived based on the Markov chain and conditional probability. Then, a calculation model for the capacity of mixed traffic flow was constructed by considering the features of lane management strategies, and sensitivity analyses were performed on the model parameters. Finally, a joint optimization model of CAVs dedicated lanes is proposed with the objective of maximum throughput based on constraints such as lane operation strategies, vehicle type ratios, and road resources. The numerical experiments lead to the following conclusions. (1) For two-lane highways, when the traffic demand is less than 6000 veh/h, the mixed driving lane management strategy should be applied; and when the traffic demand reaches 8000 veh/h, and the CAVs penetration rate is more than 0.56, one CAVs dedicated lane is required. Also, the higher the traffic demand, the lower the critical penetration rate of CAVs. (2) In the three-lane highway scenario, no dedicated lane is required when traffic demand is less than 8000 veh/h; one CAVs dedicated lane is needed when demand exceeds 8000 veh/h with CAVs penetration rate greater than 0.38; and two CAVs dedicated lanes are necessary when demand increases to 12800 veh/h and CAVs penetration rate is more than 0.79. (3) As for four-lane highways, the minimum traffic demand for installing one dedicated lane is 15600 veh/h, and the critical penetration rates for one, two, and three dedicated lanes are 0.32, 0.71, and 0.96, respectively. (4) The increase of CAVs dedicated lane usage willingness and platoon size promote the throughput, and the former CAVs dedicated lane usage willingness works more obviously. These research conclusions can provide theoretical and applied practical support for CAVs dedicated lanes management in the future.

Impact of climate change on carbon emissions in future road design: frost protection of roads in temperate climates

The aim of this case study was to estimate the impact of future adaptation to climate change with respect to frost on emissions from road construction. Based on the Representative Concentration Pathways (RCPs) published by the Intergovernmental Panel for Climate Change, the Norwegian Centre for Climate Services has predicted statistical frost quantities for the years 2071–2100 in Norway. Carbon emissions in production, loading, transportation, and construction related to the frost protection of roads were estimated based on the predictions and compared with frost protection based on frost quantities for the years 1981–2010. The case study covered two recently constructed four-lane highways in Norway that represent areas with minor and major frost quantities. Three alternative power sources for machinery and transportation were studied: fossil fuel, biofuel, and electricity. These alternatives were combined with two scenarios for climate change (RCPs): one intermediate (RCP4.5) and one business-as-usual scenario (RCP8.5). Based on the combined alternatives and RCPs, the estimated reduction in CO2-equivalents ranged from 22% to 90%.

Life Cycle Carbon Emissions and an Uncertainty Analysis of Recycled Asphalt Mixtures

The efficient recycling of road materials is an effective way to reduce carbon emissions. Approximately 400 million tons of waste asphalt pavement materials is generated annually in China, but the utilization rate is less than 50%. In this paper, a whole life cycle CO2 emission calculation model for recycled asphalt mixtures is established, and an uncertainty analysis is carried out on the basis of this model. The steps in the recycled asphalt mixture stage with the greatest impact on emissions are identified. The life cycle of asphalt mixtures is divided into raw material production, mixture preparation, material transportation and construction phases based on the carbon emission trends in the four phases. First, recycled asphalt mixtures are considered, and the carbon emissions along a two-way four-lane highway are analyzed based on the relevant carbon emission factor and other known data. The carbon dioxide emissions of each stage are also compared to identify the key links among stages. Then, the carbon emissions of hot-recycled asphalt mixtures are compared with those of ordinary asphalt mixtures and cold-recycled asphalt mixtures in each stage. Finally, an analytical uncertainty study of recycled asphalt mixtures is conducted using uncertainty modeling in different scenarios. Based on the quantitative results of the carbon emission calculations through life cycle assessment (LCA), future measures for reducing carbon emissions from recycled asphalt mixtures are proposed.

Assessment of Motor Vehicle Noise Levels on the Territory of New Residential Complexes in Voronezh City

Introduction: Adverse human health effects of motor vehicle noise, which levels are the highest in urban areas, are considered in many foreign and domestic studies. Objective: To establish the zone of acoustic discomfort related to motor vehicle noise on the territory of new residential complexes in the city of Voronezh. Materials and methods: Using the “Assistant” sound level meter (accuracy class 1), we conducted 72 noise measurements at 36 monitoring points within the 20.5 hectare area of two residential complexes at distances of 7.5, 50, 100, 200, 300, 350, and 430 meters from the four-lane highway, the main local source of traffic noise. The measurements were taken in May 2023 on working days (Monday to Friday) in the daytime and at night. Results: We have established that modern urban planning technologies and solutions used in the construction of new residential complexes are unable to eliminate the zone of acoustic discomfort. According to the results of field measurements, the equivalent noise level along the highway in the daytime exceeds permissible levels by 17.8–19.7 dBA and at night – by 22.6–25.7 dBA. The noise limit is also exceeded in the inner yard (on the playground, in the recreation area). The significant area of the study object is almost completely affected by traffic noise at the distances of up to 100 m and 200 m in the daytime and at night, respectively, which creates an unfavorable acoustic environment that has a negative impact on the local residents. Conclusions: To reduce the area of the acoustic discomfort zone, it is recommended to take measures to reduce traffic intensity in the study area by developing the road network and public transport system, prohibiting motorcycle and freight traffic on this street, especially at nighttime, improving landscaping of the adjoining territory, and installing transparent noise barriers that will prevent noise transfer between houses to the inner territory of the residential complex and the lower floors of the buildings.

Assessing the crash risk of mixed traffic on multilane rural highways using a proactive safety approach

The crash risk assessment of mixed traffic has been understudied due to a lack of pertinent data. In recent years, proactive methods have gained significant attention in transportation safety analysis because of their numerous advantages. In this study, we model and evaluate the effect of speed difference on the sideswipe crash risk of mixed traffic using a novel proactive safety indicator called Anticipated Collision Time (ACT). For analysis, detailed trajectory data were collected using an unmanned aerial vehicle from four-lane and six-lane rural highways. The crash risk was derived from the observed conflict risk and then used to assess the highway system's safety performance under study. Using the Extreme Value Theory (EVT), the conflict risk was mapped to the crash risk. The extreme events were identified using the Block Maxima (BM) approach. Later, the Generalized Extreme Value Distribution (GEV) models were developed for each location by extracting the sideswipe conflicts from the vehicle trajectories. The findings suggest that sideswipe conflicts are more of a safety concern than rear-end conflicts due to the frequent nature of lane changes or passing operations. Also, significant speed difference exists among different vehicle modes present in mixed traffic, and the sideswipe crash risk increases with the increase in the maximum speed difference. The analyses of speed differences also indicate that compared to the four-lane highway, the available safety margin is limited on a six-lane highway due to the higher maximum speed difference. Hence, any driver error may lead to sideswipe crashes. In light of the findings of this study, we strongly suggest the need to provide speed control strategies and restrict the frequent risky lane-changing or passing operations that mainly give rise to sideswipe conflicts on a six-lane highway. Further, this study found that the sideswipe crash risk decreases with the increase in vehicle size on both four-lane and six-lane highways. Hence, we suggest developing separate crash risk models for different vehicle modes in mixed traffic on multilane rural highways. Otherwise, the crash risk mitigation strategies may not be appropriate for mixed traffic conditions.

Dynamic Responses of Padma Multipurpose Bridge Truss due to Moving Train Load

Padma Multipurpose Bridge (PMB) is one of the most important projects in the history of Bangladesh due to its regional importance, economic benefit, and primary connectivity of one-third population of the country. The bridge is 6.15km long, connecting the ends of Mawa and Janjira in Bangladesh. The entire project is challenging to construct and complex in design as it contains both four-lane highways and train tracks supported by a double-deck composite warren truss. In this study, the dynamic response of the truss due to the moving train has been analyzed using the Moving Element Method (MEM). In this process, a separate finite element model has been developed using Finite Element (FE) program to convert the double deck truss into an equivalent beam. Analysis has been conducted for a series of different load cases, converging to the most realistic case where the actual train parameters are considered. Parametric studies have been carried out to determine the dynamic responses of the bridge with varying pier spacing and speed of the train. The most optimal solution has been discussed with the effect of the vibration of the train acting on the multi-purpose Padma bridge. The bridge's dynamic amplification factor (DAF) at a design speed of below 100km/hr is found 1.05. The parametric study shows that the critical train speed for the PMB is 1400km/hr resulting in the bridge resonance with a DAF of 18. It is also evident that with the increase of pier spacing the resonance of the bridge is expected to occur at a relatively lower speed.

Research on the Safety of the Left Hard Shoulder in a Multi-Lane Highway Based on Safety Performance Function

The left hard shoulder plays an important role in the event of an emergency on the inside of a multi-lane highway, but past studies have not been able to clarify the criteria for its installation or quantify the safety impact of its installation on the left side. In order to study the influence of the left hard shoulder on the safety of vehicles traveling on multi-lane highways, based on past studies that only studied the situation of four-lane highways, this paper firstly constructs a multi-lane highway simulation model under different numbers of lanes based on the VISSIM traffic simulation and uses Surrogate Safety Assessment Model (SSAM) to study the conflict characteristics of multi-lane highway vehicles under different numbers of lanes. Based on the above findings, this paper introduces the Safety Performance Function (SPF) to construct a multi-lane freeway accident prediction model, calibrates the model by adding the indexes affected by the left side hard shoulder to the basic prediction mode, and uses the historical accident data of the Badou-Shihu section of the Guangdong Northern Second Ring Highway as the basis to study the differences in accident rates of the investigated section before and after setting the left hard shoulder. The study showed that the average Time to Collision (TTC) increased by 57.2%, Maximum Deceleration (MaxD) increased by 19.2%, and Delta Speed (DeltaS) increased by 15.3% after setting hard shoulders on the left side of multi-lane freeways, and traffic conflicts on multi-lane freeways were significantly reduced, and safety was improved considerably. In addition, the rear-end conflict rate decreased by 0.17%, 0.75%, and 4.6% after setting hard shoulders on the left side of one-way three, four, and five lanes, respectively, indicating that hard shoulders on the left side are the most effective in improving the safety of one-way five-lane freeways. The accident prediction results show that within the reasonable setting range of the left hard shoulder width (0~4 m), the accident rate decreases by about 1.5% for every 0.5 m increase if only the influence of the left hard shoulder width is considered. Without considering other factors, increasing the width of the hard shoulder on the left side can reduce the number of accidents. This indicates a significant safety improvement for a one-way five-lane highway after setting the hard shoulder on the left side, and the conclusion is consistent with the simulation results. In this paper, based on past research, the research object is extended to one-way three-, four-, and five-lane highways. The findings of this paper can help the road authorities develop specifications for installing hard shoulders on the left side of multi-lane freeways and adopt strategies to improve the traffic safety level of multi-lane freeways. In addition, the models and methods used in this paper can also help build a framework for future intelligent networked vehicle avoidance systems and promote the development of intelligent networked technologies.

Overview of River Hydrological Issues in Kakarbhitta-Pathlaiya Road Segment of East-West Highway of Nepal

The East-West Highway of Nepal is the main trade and physical mobility corridor and of a two-lane bituminous road. Therefore, the Government of Nepal (GoN) is planning to improve it to a standard four-lane highway. In the first phase, the Government of Nepal is planning to upgrade the Kakarbhitta-Pathlaiya road which is the segment of the East-West Highway. It is vital to examine the river hydrology accurately for the appropriate location and design of the structures associated with it. This study aims to work out the features of flood and sediment of the major rivers intersecting the Kakarbhitta-Pathlaiya road. A review of the previous studies and field observation via a walk-through survey was conducted to assess the hydrological issues. The road segment passes through the Terai. The study revealed that the issues of flooding and inundation within the Terai are more critical, and the rivers crossing the road segment transport significant amounts of sediment as well. In the stages of planning and design of the road segment, the capacity of the rivers must be enhanced for transporting water and sediment in the places of bridges. Besides, watershed management techniques and integrated water resources management approaches should be intervened.

Finite mixture Negative Binomial-Lindley for modeling heterogeneous crash data with many zero observations

Crash data are often highly dispersed; it may also include a large amount of zero observations or have a long tail. The traditional Negative Binomial (NB) model cannot model these data properly. To overcome this issue, the Negative Binomial-Lindley (NB-L) model has been proposed as an alternative to the NB to analyze data with these characteristics. Research studies have shown that the NB-L model provides a superior performance compared to the NB when data include numerous zero observations or have a long tail. In addition, crash data are often collected from sites with different spatial or temporal characteristics. Therefore, it is not unusual to assume that crash data are drawn from multiple subpopulations. Finite mixture models are powerful tools that can be used to account for underlying subpopulations and capture the population heterogeneity. This research documents the derivations and characteristics of the Finite mixture NB-L model (FMNB-L) to analyze data generated from heterogeneous subpopulations with many zero observations and a long tail. We demonstrated the application of the model to identify subpopulations with a simulation study. We then used the FMNB-L model to estimate statistical models for Texas four-lane freeway crashes. These data have unique characteristics; it is highly dispersed, have many locations with very large number of crashes, as well as significant number of locations with zero crash. We used multiple goodness-of-fit metrics to compare the FMNB-L model with the NB, NB-L, and the finite mixture NB models. The FMNB-L identified two subpopulations in datasets. The results show a significantly better fit by the FMNB-L compared to other analyzed models.

The Spatial Estimation of Expected Accident Frequency of Rural Divided Four-Lane Highways in Order to Exposure Variables and Cmf (Case Study: Main Roads Network of Hamedan Province)

The Spatial Estimation of Expected Accident Frequency of Rural Divided Four-Lane Highways in Order to Exposure Variables and Cmf (Case Study: Main Roads Network of Hamedan Province)

Traffic-Aware Lane Change Advance Warning System for Delay Reduction at Congested Freeway Diverge Areas

This paper presents an on-board advance warning system for vehicles based on a probabilistic prediction model that advises them on when to change lanes to reach a highway diverge on time. The system is based on a model that estimates the probability of reaching a goal state on the road using one or multiple lane changes. This estimate is based on several traffic-related parameters such as the distribution of inter-vehicle headway distances as well as driver-related parameters like lane change duration. For an upcoming diverge, the advance warning system uses the model to continuously calculate the probability of reaching it and advise the driver to change lanes when the probability dips below a certain threshold. To evaluate the performance of the proposed system in reducing traffic delay at highway diverges, it was used on a segment of a four-lane highway to advise vehicles taking an off-ramp on when to change lanes. Results show that using the proposed system reduces average delay up to 6% and maximum delay up to 16%, depending on traffic flow and the ratio of vehicles taking the off-ramp.

The Performance of a Low Berm in Reducing Traffic Noise

Traffic noise measurements were made behind a low, earth berm and in an adjacent open field to estimate insertion loss. The traffic was comprised of a mix of light vehicles, heavy trucks, and some medium trucks. The berm had a height of 1.65 meters above the roadway and began at the outside shoulder of a four-lane highway along U.S. Highway 101 in Northern California. Two microphone positions were located on the far side of the berm at distances of 28 and 40 meters from the center of the near lane of vehicular traffic. Away from the berm, a microphone was placed in an open field at 28 meters from the highway at a site upstream of the berm. The difference between the open location and those behind the berm were 11.6 and 9.9 dB for the 28- and 40-meter locations, respectively. The reductions obtained with the berm are compared to double edge diffraction theory and acoustic scale model results from the literature. The results of this study are reviewed in this paper and a comparison to FHWA Traffic Noise Model results is presented.

Investigations on development of early distresses on bituminous pavement in India and remedies

In the present study, reasons for early distresses noticed on the bituminous pavement of a four-lane divided highway between the Pardi and Agrasen sections of National Highway 6 from km 498.000 to km 544.000, in India, were investigated. The total length of the road project is 46 km. A detailed pavement condition mapping was carried out, and various distresses were noticed on the surface. To assess the reasons for the distresses, combined cores of the bitumen surface course and the base course were taken from 57 locations, 29 on the left-hand side and 28 on the right-hand side of the carriageway, and mix properties were evaluated in the laboratory. The investigation on the mixes revealed that bituminous cores collected from both the surface course and binder course have no resemblance to the job mix formula. Non-homogeneity of layer thicknesses, variation in mix properties, variation in aggregate gradation and high filler–binder ratios were observed. Aside from the laboratory investigation, the physical condition of bitumen cores was studied and the conditions of the pavement layers were assessed based on the deflection basin parameters. This paper presents a systematic procedure adopted for identifying the causes of early distresses, and appropriate treatments are suggested for rectification.

Factors influencing bat road casualties in a Neotropical savanna

Collision with vehicles is one of the main causes of death for many vertebrates; however, little is known about bat roadkill. Thus, in this study we described bat roadkill in an area of Neotropical savanna and evaluated factors potentially affecting its occurrence. We surveyed 114km of roads on the margins of protected areas in the Brazilian Federal District for 5 years. We analysed bat roadkill on three types of roads (dirt roads, two-lane paved highways, and four-lane paved highways) and recorded distance from water and presence of artificial light. Bat roadkill was calculated for 2-km sections and analysed using generalized linear mixed models (GLMMs) with the following independent variables: season, road type, presence of light, and distance from water. We used section nested within road as a random effect. We estimated a total of 4740 roadkilled bats and identified individuals from three families. Bat road casualties were more numerous in the rainy season and on four-lane highways, whereas proximity to water and presence of artificial light were not related to roadkill number. The higher roadkill rate during the rainy season may be explained by higher bat activity due to the increased availability of resources. Regarding the influence of road type, four-lane highways have the highest traffic volumes in the area and the highest speed limits, which are associated with higher roadkill rates. Bats represent the most diverse order of mammals in the Cerrado, where they provide many important ecological services, which need to be preserved.

Design and Implementation of Intelligent Agent Training Systems for Virtual Vehicles.

This paper presents the results of the design, simulation, and implementation of a virtual vehicle. Such a process employs the Unity videogame platform and its Machine Learning-Agents library. The virtual vehicle is implemented in Unity considering mechanisms that represent accurately the dynamics of a real automobile, such as motor torque curve, suspension system, differential, and anti-roll bar, among others. Intelligent agents are designed and implemented to drive the virtual automobile, and they are trained using imitation or reinforcement. In the former method, learning by imitation, a human expert interacts with an intelligent agent through a control interface that simulates a real vehicle; in this way, the human expert receives motion signals and has stereoscopic vision, among other capabilities. In learning by reinforcement, a reward function that stimulates the intelligent agent to exert a soft control over the virtual automobile is designed. In the training stage, the intelligent agents are introduced into a scenario that simulates a four-lane highway. In the test stage, instead, they are located in unknown roads created based on random spline curves. Finally, graphs of the telemetric variables are presented, which are obtained from the automobile dynamics when the vehicle is controlled by the intelligent agents and their human counterpart, both in the training and the test track.

Parameters Influencing Lane Flow Distribution on Multilane Freeways in PTV Vissim

Abstract In a parameter study, we systematically varied parameter values, and quantified the resulting traffic flow in each individual lane. We modeled two-, three-, and four-lane freeway sections with the microscopic traffic flow simulation tool PTV Vissim. We compared the results with findings from literature. Simulations using car following model Wiedemann 99 fit better to empirical studies than those using Wiedemann 74. Empirically determinable parameters, that have a relevant influence on lane flow distribution are desired speed distributions (mean for heavy-duty vehicles and standard deviation for cars), heavy-duty vehicle share, and the gradient of the section. Additionally, the driving behavior parameters CC1 (headway time), CC3 (threshold for entering following), and safety distance reduction factor have an influence. As CC1 is one of the most relevant parameters for calibrating capacity, CC3 and the safety distance reduction factor remain for lane flow adjustment.