Highway Facilities Research Articles

Green space in highway rest facilities “Zeroth greening”

Green space in highway rest facilities “Zeroth greening”

Automated detection of physical fatigue in transportation maintenance workers through physiological and motion data

Lifting bags of dry concrete mix has caused significant physical fatigue and work-related musculoskeletal disorders (WMSDs) in transportation maintenance workers. Detection of physical fatigue can effectively prevent developing WMSDs. However, there lacks studies exploring the automated detection of physical fatigue in transportation activities. Additionally, previous efforts on physical fatigue detection, primarily focused in the construction sector, may not be directly applicable to transportation activities, due to different activity duration, intensity, and frequency. Also, prior detection methodologies have been examined under laboratory conditions, and their efficacy in real-world environments remains unverified. Therefore, this study explored physical fatigue detection methods by conducting field experiments with 29 transportation maintenance workers lifting bags of dry concrete mix in a highway maintenance facility. Participants’ physical fatigue levels were measured using electromyography (EMG), electrodermal activity, and/or heart rate (HR) and motion data with different machine learning algorithms. Results indicated that the Fully Connected Neural Networks algorithm can achieve the highest accuracy (87.84%) with EMG, HR, and motion data for classifying physical fatigue levels in transportation maintenance workers. This study demonstrated the feasibility of automated physical fatigue detection, which can be implemented as a monitoring tool of physical fatigue for enhancing health of transportation practitioners.

A Multi-Objective Evaluation Method for Smart Highway Operation and Management

Smart highways represent a novel highway concept in the era of big data, emphasizing the synergy among people, vehicles, road facilities, and the environment. However, the operation and management of smart highways have become more intricate, surpassing the adaptability of traditional highway evaluation and management methods. This study integrates the distinctive characteristics of smart highway facilities and operational objectives to enhance and modernize the existing highway evaluation system. Drawing from research on smart highway construction projects, a smart highway evaluation system encompassing facility structure, electromechanical facilities, and operation services is formulated based on a hierarchical analysis method. The quantitative evaluation of each indicator is achieved by combining existing specifications and expert questionnaire solicitation. The group decision-making method is initially employed to optimize subjective weights, followed by the calculation of combined weights using both the entropy weight method and critic method in objective evaluation. Finally, a comprehensive evaluation model is established and validated through engineering projects. The results demonstrate that the evaluation system effectively highlights the advantages and disadvantages in the operation and management of smart highways, thereby fostering the advancement of smart highway iteration.

Legibility of variable message signs on foggy highway: Effect of text color and spacing

Variable message signs are frequently utilized as highway communication facilities to inform vehicles about the state of the roads and the weather. However, standards and design specifications for variable message signs are unclear. This study examines the effect of the own factors and environmental factors on the legibility of variable message signs in order to optimize the design of variable message signs on highways. Three font colors (green, red, and yellow) and three levels of word spacing (0.1H, 0.3H, and 0.5H) were chosen for the variable message signs. For the environmental factors, three different weather types were represented according to visibility, namely sunny (visibility 10,000 m), light fog (visibility = 1000), and heavy fog (visibility = 200). The legibility time and distance were recorded for 23 participants, and then the legibility of the variable message signs was analyzed. The results showed that own factors and environmental factors influenced the legibility of the variable message signs. Experiment 1 results showed that the legibility of the variable message signs was the best when the text was yellow in light fog weather conditions. Experiment 2 results showed that the legibility of the variable message signs was better than other experimental scenarios in light fog conditions with a 0.3H word spacing. The findings of this study will be used by relevant agencies to establish design guidelines for variable message signs.

Development of an evaluation indicator for highway climate change adaptation projects based on analytical hierarchy process in South Korea

AbstractOwing to climate change, abnormal climate phenomena occur frequently, damaging aging highway facilities. Therefore, it is necessary to develop adaptation projects for highway systems. Adaptation projects focus on mitigating the impact of climate change on highway facilities and enabling safe use. The present study aims to develop quantified evaluation indicators that are necessary for planning and selecting appropriate climate change adaptation projects. By analysing previous studies, the most important factors to be considered in the evaluation process of climate change adaptation projects were defined, and 20 preliminary evaluation indicators were divided into three layers. A feasibility study for each class was performed on the preliminary evaluation indicators by an expert panel; 16 evaluation indicators were selected through a feasibility study, and the weight of each indicator was calculated using the analytical hierarchy process (AHP) method. The priority of the evaluation indicators was service improvement through adaptation projects (weight 8.76), cost reduction and job creation (weight 8.46), and climate change impact reduction and vulnerability reduction (weight 8.31). These quantified evaluation indicators can help organizations that manage highways respond to climate change and establish adaptation projects.

Analysis and Discussion on the Current State and Demand of Energy Supply for Highway Transportation Facilities

Energy supply is a crucial factor in realizing the future transformation of highway transportation. Determining a comprehensive and sustainable energy supply network that aligns with the demands of future highway transportation facilities - ensuring they are "safe, reliable, environmentally friendly, efficient, and sustainable" - poses a key challenge for current highway developers and operational managers. This study examines the types and energy consumption of significant energy-consuming facilities along expressways. It delves into the current state of power supply and distribution technologies for highway transportation facilities, including low-voltage, medium-voltage, and complementary wind and solar power systems. Additionally, the research analyzes existing issues within power supply and distribution systems for highway transportation facilities. The study investigates the load characteristics and spatial distribution of electricity-consuming facilities along expressways, concluding with an analysis of the future trends in energy demand for highway transportation facilities. This comprehensive exploration encompasses aspects such as the scale of energy demand, the diversification of energy supply, and the need for a secure, efficient, and intelligent energy supply. The findings aim to provide valuable insights for developing innovative, diverse energy supply, and control technologies for safe, efficient, and interconnected highway transportation facilities.

Study on the Performance of Bitumen Waste Stone Column in Soil Stabilization

Stone Column is a technique for improving and stabilising weak soils such as soft clays, silts, and loose sands, allowing highway facilities, storage tanks, embankments, and bridge abutments to be built. We are utilising bituminous waste as an alternative material for coarse aggregate in the construction of stone columns to save expenditure by partially replacing coarse aggregate with bituminous waste. We're mixing bitumen waste and coarse aggregate, which have been passed through a 16 mm IS sieve and are being retained . Different mix proportions of coarse aggregate and bitumen waste for stone column samples represented as (X% aggregate + Y% bitumen waste) were tested such as (100%C), (70%C+30%B), (60%C+40%B), (50%C+50%B) and (100%B). Intermediate Plastic Clayey soil (CI) at OMC was used as the test sample in which stone column was installed. The CBR test was performed on the stone column with a diameter of 50 mm and depth of 100 mm installed in the compacted soil in CBR mould to determine CBR value and bearing capacity of samples. After that the results were compared with 100% coarse aggregate stone column sample (100%C).

Moving Vehicle Method to Calculate Traffic Flow Characteristics for Erbil 60m Ring Road

Traffic flow characteristics are important factors in the planning and management of highway facilities. Such information is not available in systematic form of the city of Erbil, so this study aims to obtain required data on flow, speed and density accordingly to find the relationship between these three parameters. Travel time, travel speed and flow due to traffic interaction data are also needed to evaluate the existing levels of service which is necessary for transportation planning and economic analysis, to be done in this field. This study uses the directional distribution of several selected road sections in the city of Erbil to give a complete picture of traffic flow in terms of size, daily and hourly variabilities. It was for this purpose that 60m ring road in Erbil city was chosen. To evaluate the data, software such as (Microsoft Excel, SPSS) were used in-order to develop relationships among each pair of flow type variables (density, speed and flow). Measuring strength of the relationships between speed-density, flow-density and speed-flow should be done. The relation between traffic flows data was found by the R² is applied for all models. The strength of relationships among speed-density, flow-density and speed-flow should be measured. The relation between traffic flows data was found by the R² is applied for all modes. The maximum flow rate in Section 9 is over 9000 pc/hr but range of flow is equal to 7605 pc/hr and range of space mean speed is it among 20 and 55 km/hr at peak hour and highest range of density is among 40 and 160 pc/km.

Reliable capacity of electronic toll collection lanes

For proper planning, design and operation of an electronic highway toll facility, the capacity of the toll lane is an important aspect that needs to be considered. Although the capacities of roads and intersections are generally referred to as stochastic in nature, toll lane capacity is still considered as a deterministic value. A study was undertaken into the variation in service headway and thus reliability related to capacity values for toll lanes. Videographic traffic data were collected at three electronic toll plazas in India. The service headway of cars was found to be lower compared to vehicles with trailers. A Monte Carlo simulation was used to generate the different variations that may occur in the service headway owing to supply-side and demand-side changes. Finally, the capacity for 80%, 90% and 95% reliability was found as 494, 554 and 608 passenger cars per hour, respectively. The developed capacity values can be used to check the volume-to-capacity ratio in a mixed traffic lane and can be used to develop the level-of-service thresholds for electronic toll collection lanes in future studies.

Influence Area at Signalized and Stop-Control Intersections: Operational Analysis

Understanding the influence of intersections on operating conditions along connecting roadway segments is important for the analysis of highway facilities and corridors. This study aims at assessing the influence area at signalized and stop-control intersections along rural corridors. The study used speed as a performance measure in examining the spatial extent of operational effects at intersections. High-fidelity connected vehicle (CV) trajectory data, collected at 11 different sites in Florida, was used in this study. The CV trajectory data consists of individual waypoints that included timestamps and location coordinates along with other attributes. Drivers’ speed profiles while driving through the intersection were established and analyzed to determine the length of upstream and downstream influence areas. Quantile regression models were developed to estimate the 50th, 70th, and 85th percentiles of upstream and downstream influence areas separately for signalized and stop-control intersections. Study results indicate that the upstream influence area is longer for a signalized intersection than for a stop-control intersection for comparable segment running speeds. Further, the downstream influence area is significantly longer than the upstream influence area at signalized intersections, and this was consistent at all study sites. Traffic flow level did not have a significant effect on the upstream or downstream influence area; however, midblock running speed, percent heavy vehicles, and facility type (multilane versus two-lane) were found to significantly affect the upstream and downstream influence areas at signalized intersections.

Quantifying Operational Impacts of Variations in Work Zone Setups, Traffic Demand, and Traffic Composition: A Case Study

The presence of work zones due to pavement repair and rehabilitation is very common in highway facilities. Lane closures associated with work zones result in capacity reduction, which, in turn, often leads to increased congestion at such locations. This paper documents findings from a study that investigated the performance of freeway facilities in the presence of work zones under various Temporary Traffic Control (TTC) and lane closure scenarios while taking under consideration traffic composition and driving behaviors. The study site was an approximately 10-mile freeway segment of Interstate 65 (I-65) located in Birmingham, AL. The testbed was coded in PTV VISSIM, a microscopic simulation analysis platform, for: 1) baseline conditions (i.e., no work zone presence) and 2) work zone conditions with single lane closure (i.e., 3-to-2 lane closure). Work zone scenarios were coded for two TTC strategies, namely, early merge and late merge control and for three different positions of the lane closure (i.e., left, right, and center lane closures). The length of the work zones varied from 1000 to 2000, and 3000 ft. Sensitivity analysis was performed to document the operational impacts of varying heavy vehicle percentages, changes in drivers’ aggressiveness, and projected traffic demand changes. The impacts were quantified using linked-based measures of effectiveness (MOEs) such as travel time, and travel time index. The study results show that there is no significant change in travel time index due to the variation of work zone length across the study corridor. Under similar traffic control and demand conditions, a center lane closure consistently results in significantly higher travel time index than a left or right lane closure and should be avoided. Consideration of operational impacts of changes in truck percentage indicates that the corridor can absorb an increase in truck percentage from 10% to 15%, while performance rapidly deteriorates when a higher percentage of trucks is present in the traffic stream. The study findings can be used to guide transportation agencies in their future efforts to develop strategic lane closure plans that minimize congestion.

Research on Highway Traffic Safety and Facility Optimization

Traffic safety is one of the problems that need to be addressed in the construction and development of expressway. The key content of the design of traffic safety facilities is optimizing traffic safety facilities to reduce the probability of traffic safety accidents. Based on the analysis of highway safety facilities design optimization requirements, this paper puts forward the corresponding optimization measures, and explores the innovation of safety facilities design, in hopes of providing reference for the design of highway safety facilities.

Localizing safety performance functions for two-way STOP-controlled (TWST) three-leg intersections on rural two-lane two-way (TLTW) roadways in Alabama: A geospatial modeling approach with clustering analysis

Safety Performance Functions (SPFs) can be used to predict the number of crashes for highway facilities by site characteristics, including traffic exposures and other specific site factors. The traditional approach to developing SPFs relies on factors that are observed in the data and has an unstated assumption that the relationships between safety performance and observed factors are stationary. However, there might be factors that are not captured by the data but also have significant impacts on roadway safety performance. These factors can lead to significant unobserved heterogeneity in safety performance at different sites. Failure to capture such unobserved heterogeneity in developing SPFs may result in biases and decrease the predictive accuracy. Given the interactions between highway traffic and roadway environments, the unobserved heterogeneity is likely related to the geographic space of the highway network. This study employs a spatial modeling approach, namely Geographically Weighted Negative Binomial Regression (GWNBR), to incorporate spatial heterogeneity into SPF model estimation. The GWNBR model can generate a local SPF for every site instead of a global SPF for one entire jurisdiction (e.g., a state) from the traditional approach. Local SPFs (or l-SPFs) are high-resolution and may be difficult for practitioners to use. To support the implementation of l-SPFs, this study proposes a method to aggregate l-SPFs to various geographic levels. This study first uses the 2014–2018 geo-referenced crash data from Alabama to develop l-SPFs for two-way STOP-controlled (TWST) three-leg intersections on rural two-lane two-way (TLTW) roadways in the state. The results show that l-SPFs vary substantially across Alabama. For example, the coefficients of traffic volume (AADT) on major roads range from 0.126 to 1.203 across different areas of the state. Then, an aggregation method based on K-means clustering is demonstrated to aggregate l-SPFs to various geographic levels of interest. The l-SPFs and their aggregation provide geographic flexibility in developing countermeasures and allocating funds to improve traffic safety considering local conditions.

Improving Metropolitan Transportation Efficiency With FAST Miles

In America’s large and severely congested metropolitan areas, carpools and express bus service could attract many more riders if they could operate between residential areas and job centers on free-flowing highways that provide premium service opportunities. FAST Miles attempts to eliminate recurring congestion on limited-access highway systems using a potentially more publicly acceptable form of road pricing, along with an integrated multimodal strategy to encourage shifts of solo-driving commuters to alternative modes. FAST Miles allocates to motorists a limited number of free miles for use in peak periods on limited-access highways. Every motorist would get a share of free peak-period use of FAST highway facilities “already paid for” through his or her taxes through free FAST Miles credits. Total outstanding credits would be limited to ensure that the metropolitan highway system does not get congested and that express bus services operate faster, providing better levels of service at a lower cost.The concept would include new express bus and carpooling services, improved passenger collection and distribution services at bus transfer stations, free transit trial periods, web-based multimodal trip-planning programs, and individualized marketing of alternative modes at employment centers and in residential areas. Preliminary sketch analysis suggests that FAST Miles could be self-financing. It also would introduce new possibilities for public-private partnerships.

Performance Rating of National Highways Based on Road User Perspective – A Case Study of Kalka–Shimla Highway

The road network plays the most important role in the development of India’s infrastructure. Through the initiative of rating national highways, we will be able to set standards for quality highway services, and as a result, road users will receive excellent value for their money. Moreover, better quality Indian Highways will lead to safer travel experiences and consequently result in fewer road accidents and fatalities. The effort for evaluating the roads was done by US Department of Transportation in 1950s as has been highlighted in the Highway Sufficiency Rating Manual of 1952. However, these ratings were based only on efficiency and safety parameters, completely neglecting the user perspective and services. As the road users gain access to information about products and services in real time over the internet, they are more empowered than ever before. Thus, the performance evaluation of a highway stretch must include additional aspects associated with the user experience. This paper examines the real-time problems they face along the journey. National Highway authority of India (NHAI) and Ministry of Road Transport and Highways (MORTH) of India have framed Standard Operating Procedure (SOP) for assessment and rating of 4-6 lanes divided carriageway NHs based on road user perspective. Road user perspective carries a 20 per cent weightage in overall highway efficiency. A questionnaire survey was taken as part of the road user perspective study on the Kalka-Shimla NH No. 5 in the state of Himachal Pradesh in India. The highway scored 17.1 marks out of 20 based on users’ response, representing an 85.5% score, and indicating minor deficiencies regarding the selected highway facilities.

Weather-Based Lane-Change Microsimulation Parameters for Safety and Operational Performance Evaluation of Weaving and Basic Freeway Segments

It is well recognized that adverse weather conditions have significant negative impacts on safety and mobility of transportation systems. Microsimulation modeling has emerged as a cost-effective tool to quantify the safety and operational effects arising from adverse weather. Developing a realistic microsimulation model necessitates adjusting driving behavior models through trajectory-level data. This study contributes a methodology to update lane-change parameters to develop weather-specific microsimulation models based on different freeway facilities, and ultimately evaluate the safety and operational performance of the roadways. Representative parameters in various weather and facility types were extracted using an automated process. As part of the comprehensive assessment of the adjusted parameters, a weaving section and a basic freeway segment on Interstate 80 in Wyoming were identified as potential candidates. The safety and operational analyses were conducted using VISSIM. Various simulation scenarios were designed based on the field traffic flow data. The safety analysis using three surrogate measures of safety including time-to-collision, deceleration rate to avoid collision, and post encroachment time revealed that adverse weather generated a higher number of conflicts than did clear weather for both facilities. The operational analysis suggested that adverse weather produced lower average speed and higher total travel time and delay than clear weather. The demonstrated methodology could be used in assessing various connected vehicle applications associated with lane change in microsimulation from safety and operational perspectives and could be adopted by transportation agencies to develop weather-based microsimulation models.

Safety Prediction Method for Freeway Facilities with High-Occupancy Lanes

The objective of this paper is to describe the development of a safety prediction method for freeways with high-occupancy vehicle (HOV) and high-occupancy toll (HOT) lanes, collectively referred to as HO lanes. This method has been developed and documented in a manner that is consistent with the safety evaluation methods in Part C of the Highway Safety Manual (HSM). Such a predictive methodology would assist state departments of transportation in explicitly considering safety performance impacts when planning, designing, and operating freeway facilities with HO lanes. Data were collected in California and Washington to support development of the predictive methodology. This method focuses on the evaluation of one freeway travel direction with each application. The paper summarizes key differences and similarities between this method and the current predictive method for freeways in Chapter 18 of the HSM Supplement. The method includes models for predicting total crash frequency and multiple-vehicle crash frequency. The method applies to freeway facilities with continuous HO lane access, buffer-separated HO lanes with intermittent access, and barrier/pylon-separate HO lanes with intermittent access between the HO lane(s) and the general-purpose lanes. The method does not differentiate between HOV and HOT designation.

Exploratory Evaluation of Incentives to Increase High-Occupancy Vehicle Use on Priced Highway Facilities

This paper introduces an innovative way to incentivize increased person throughput on priced highway facilities such as toll roads, express toll lanes, and high-occupancy toll (HOT) lanes, using cash rewards for carpoolers and transit riders. An exploratory evaluation of the concept is demonstrated for the I-66 HOT facility inside the Capital Beltway in Northern Virginia. The results of the analysis suggest that the concept could provide significant benefits at a relatively low cost to public agencies for cash incentives.

Short-Term Segment-Level Crash Risk Prediction Using Advanced Data Modeling with Proactive and Reactive Crash Data

Highway crashes, along with the property damage, personal injuries, and fatalities that they cause, continue to present one of the most significant and critical transportation problems. At the same time, provision of safe travel is one of the main goals of any transportation system. For this reason, both in transportation research and practice much attention has been given to the analysis and modeling of traffic crashes, including the development of models that can be applied to predict crash occurrence and crash severity. In general, such models assess short-term crash risks at a given highway facility, thus providing intelligence that can be used to identify and implement traffic operations strategies for crash mitigation and prevention. This paper presents several crash risk and injury severity assessment models applied at a highway segment level, considering the input data that is typically collected or readily available to most transportation agencies in real-time and at a regional network scale, which would render them readily applicable in practice. The input data included roadway geometry characteristics, traffic flow characteristics, and weather condition data. The paper develops, tests, and compares the performance of models that employ Random effects Bayesian Logistics Regression, Gaussian Naïve Bayes, K-Nearest Neighbor, Random Forest, and Gradient Boosting Machine methods. The paper applies random oversampling examples (ROSE) method to deal with the problem of data imbalance associated with the injury severity analysis. The models were trained and tested using a dataset of 10,155 crashes that occurred on two interstate highways in New Jersey over a two-year period. The paper also analyzes the potential improvement in the prediction abilities of the tested models by adding reactive data to the analysis. To that end, traffic crashes were classified in multiple classes based on the driver age and the vehicle age to assess the impact of these attributes on driver injury severity outcomes. The results of this analysis are promising, showing that the simultaneous use of reactive and proactive data can improve the prediction performance of the presented models.

Capacity Analysis Framework for Freeway Ramp Weaves

AbstractThe Highway Capacity Manual 6th Edition (HCM6) provides methods for evaluating freeway segments and facilities, including weaving segments. Recent research has cast doubt on the validity of...