Six-lane Road Research Articles

Development of Capacity Estimation Models for Multi-lane Roads under Heterogeneous Traffic Conditions

The objective of this study is to develop capacity models to estimate the traffic carrying capacity of multi-lane roads with heterogeneous traffic flows. Since capacity is an important parameter in traffic engineering studies, it is vital that it is accurately estimated. Most of the current capacity estimation methodologies available are developed based on homogeneous traffic flows and hence not conducive for use in heterogeneous traffic conditions observed in Sri Lanka. Therefore, this study is done to fulfill the requirement of a capacity estimation model for this purpose. Fifty midblock sections were surveyed using manual flow data collection methods and a novel Google Application Program Interface (API) based method for speed data collection. Based on the collected data, capacity values were developed following the fundamentals of traffic flow. Regression models were built to estimate four-lane and six-lane capacity values based on roadway characteristics such as effective lane width, access point density, median type, and built environment condition. Separate models were developed because the impact these characteristics have on four-lane and six-lane roads are different. The models showed good fit with R2 values of 0.81 and 0.86 for four-lane and six-lane roads, respectively. The base capacity value of a four-lane urban road was estimated to be 2044 pcu/h/l and for a six-lane sub-urban road section 2108 pcu/h/l. The outcomes of this study can be used to develop capacity guidelines in countries with heterogeneous traffic conditions for capacity estimation.

QUALITY MANAGEMENT PRACTICES IN GONDRANG-PULCHOWK SIX-LANE ROAD UPGRADING PROJECT AT CHITWAN DISTRICT, NEPAL

The objective of this study is to assess the current quality management practices, determine the factors affecting quality management and to find out remedial measures that will improve the quality management practices in Gondrang-Pulchowk six-lane road construction project.This research methodology is based on interviews and questionnaires survey with clients and contractors who were involved in the project as well as experts from related field. Statistical tools, relative importance index, validity and reliability tests, Spearman’s correlation tests were used for the ranking of different quality aspects.From the comparative study, it was found that most guidelines of the General Conditions of Contract, Special Specifications and Quality Assurance Plan of the contract document were met during project execution although few concerns of safety and correspondence remain to be addressed.From the questionnaire survey, it was found that the practices to achieve quality need to be improved. Contractors consider cost factors as major factor affecting quality in the project whereas lack of supervision by contractors is cited by the clients as major factor affecting quality. To overcome the challenges of quality, proper material selection and usage, inspection, quality training, setting up quality department are seen as remedial measures. Improving safety at site, maintaining written correspondence, incorporating elements of ISO, proper selection and usage of materials, holding quality trainings and setting up quality control department are recommended for this project.

City-oriented and inclusive bicycle-vehicle crash frequency modeling through the integration of bicycle-sharing system and other surrogates

This research explores a city-oriented and inclusive bicycle-vehicle crash frequency model through the integration of bicycle-sharing system and other surrogates pertaining to the built environment like road network, land use developments, and socio-demographic characteristics. Bicycle-vehicle crash data from 2016 to 2019, along with the road network, land use, and socio-demographic characteristics within a 1-mile radius of 62 randomly selected Capital Bikeshare (CaBi) stations (referred to as stations), was used to estimate and validate bicycle-vehicle crash frequency models (negative binomial regression models with log-link distribution) and assess the role of explanatory variables. The selected stations are geographically and fairly distributed in low-risk, moderate-risk, high-risk, and very high-risk areas while covering 99.8% of the total number of recorded bicycle-vehicle crashes. From such an inclusive approach, it was observed that bicyclists are more likely to be involved in crashes in commercial, mixed-use, and densely populated areas. In addition, they are more often involved in crashes in areas with more six-lane roads. Also, many bicycle-vehicle crashes have occurred at intersections. The nonexistence of bicycle crossings could explain this finding. The findings are substantial, and characteristics related to the built environment like road network (including vehicle and bicycle infrastructure), land use developments, and socio-demographics are good surrogates for traffic volume and bicycle count.

THE PROCEDURE OF ANALYSIS, ASSESSMENT AND RISK REDUCTION OF VEHICLE COLLISIONS ON A MULTI-LANE ROAD

Statement of the problem. The problem of ensuring the safety of vehicles on a multi-lane roadway of the required width of coverage is considered based on the risk-oriented approach, in accordance with the Federal law of the Russian Federation No. 184 -- FZ "on technical regulation". Results. The authors presented the applicability of the algorithm to assess the risk of interaction of vehicles on six-lane highways for determining regulatory performance; identify the required values of coating thickness for the design; decision-making on the improvement of the transverse profile when major repairs and reconstruction, as well as to develop recommendations for ODD. Conclusions. It was found that in normative documents for design of six-lane roads, the design vehicle should provide the change of normalized coating thickness, increasing it to values at which the risk of collision of vehicles does not exceed the permissible value.

High NO2 Concentrations Measured by Passive Samplers in Czech Cities: Unresolved Aftermath of Dieselgate?

This work examines the effects of two problematic trends in diesel passenger car emissions—increasing NO2/NOx ratio by conversion of NO into NO2 in catalysts and a disparity between the emission limit and the actual emissions in everyday driving—on ambient air quality in Prague. NO2 concentrations were measured by 104 membrane-closed Palmes passive samplers at 65 locations in Prague in March–April and September–October of 2019. NO2 concentrations measured by city stations during those periods were comparable with the average values during 2016–2019. The average measured NO2 concentrations at the selected locations, after correcting for the 18.5% positive bias of samplers co-located with a monitoring station, were 36 µg/m3 (range 16–69 µg/m3, median 35 µg/m3), with the EU annual limit of 40 µg/m3 exceeded at 32% of locations. The NO2 concentrations have correlated well (R2 = 0.76) with the 2019 average daily vehicle counts, corrected for additional emissions due to uphill travel and intersections. In addition to expected “hot-spots” at busy intersections in the city center, new ones were identified, i.e., along a six-lane road V Holešovičkách. Comparison of data from six monitoring stations during 15 March–30 April 2020 travel restrictions with the same period in 2016–2019 revealed an overall reduction of NO2 and even a larger reduction of NO. The spatial analysis of data from passive samplers and time analysis of data during the travel restrictions both demonstrate a consistent positive correlation between traffic intensity and NO2 concentrations along/near the travel path. The slow pace of NO2 reductions in Prague suggests that stricter vehicle NOx emission limits, introduced in the last decade or two, have so far failed to sufficiently reduce the ambient NO2 concentrations, and there is no clear sign of remedy of Dieselgate NOx excess emissions.

Simulation study on effect of permeable pavement on reducing flood risk of urban runoff

Permeable pavement is part of the low impact development (LID) measurement, which can decrease urban surface runoff coefficient and flood peak flow. In this paper, a two-way, six-lane road in Nanjing was selected as the study area. Storm water management model (SWMM) was used to simulate the effect of different pavement structures (drainage surface, permeable pavement and permeable road) under different rainfall conditions on reducing surface runoff and controlling urban stormwater. The simulation results show that the drainage surface can reduce part of surface runoff, but it has no influence on the reduction and hysteresis of flood peak. The permeable pavement can reduce part of surface runoff and flood peak and can delay peak time. The permeable road has better effect on reducing runoff coefficient and flood peak, which can effectively reduce the pressure of urban drainage and reduce the risk of stormwater flood.

Modelling U-Turning Behaviour of Vehicles at Mid-Block Median Openings in Multilane Urban Roads

Gap acceptance and lateral placing of vehicles are considered as prime parameters for analysing the behaviour of U-turning in vehicles at un-signalized median opening in urban areas. Critical gap is the sole parameter in gap acceptance phenomenon where critical position gives the vehicle’s location during U-turn operation. Data for this study were collected using video photography at six median openings on a sixlane road and three median openings on a four-lane road from two different cities of India. Data as extracted by categorizing the traffic stream into five different classes such as two-wheelers, three-wheelers, car/SUVs, LCVs (light commercial vehicles) and HCVs (heavy commercial vehicles). Three different methodologies (namely the traditional method, INAFOGA and modified Raff’s method) were utilized to estimate the critical gap. Critical position of vehicles is estimated using the markings on the pavement surface. Regression technique was used for modelling critical gap and position using different variables for each motorized mode. All the proposed models have a high coefficient of determination value which indicates its high significance level. Modelling of critical position for 3-wheelers was not framed as the P-value for each variable was higher than 0.05. The reason could be the randomness in data because of the undisciplined lateral movement of three-wheelers. A design recommendation for right turn pocket lanes near the median opening area is proposed especially for U-turning traffic based on the percentage of the U-turning traffic and maximum critical position of vehicles from the median edge.

Agent-based Modeling of Pedestrian Behavior at an Unmarked Midblock Crossing

Abstract: Illegal pedestrian behavior is considered one of the main reasons for pedestrian-related crashes. This paper provides a detailed outlook of the gap acceptance behavior of pedestrians illegally crossing at an urban midblock section of a six-lane road. A simulation model was developed to capture the illegal crossing behavior for the pedestrians using agent-based modeling techniques and implemented in Anylogic. Once calibrated to study the crossing behavior, several distributions were fed into the model to determine the best distribution that mimics the pedestrians’ movements. It was found that the normal distribution is the closest fit. The results suggest that the pedestrians add a factor ranging from 1.25-1.5 to vehicle speeds before anticipating the gap, then determine whether to cross or not. The simulation tool was found useful for replicating the illegal crossing behavior. The results from this study can be helpful in assessing the pedestrian safety and providing better crossing facilities for pedestrians in urban areas.

Conflicting volume for U-turns at uncontrolled median openings

This paper proposes a practical approach to estimate the conflicting traffic volume caused by U-turns at uncontrolled median openings under mixed traffic conditions. Data were collected at 21 median openings on multi-lane divided roads in India (i.e. 13 on six-lane and eight on four-lane). The road width at the median opening is divided into three parts: zone of severe conflict, zone of safety and unaffected zone based on the placement of the left wheel of U-turning vehicles (left-hand drive rule followed in India). The first two zones together are considered as the conflicting zone for calculating the conflicting traffic. The proportion of opposing through traffic within the conflicting zone is considered as the conflicting traffic volume for U-turns. The conflicting volume at all the sections is estimated based on placement of through traffic across the width of the road and it is found to be dependent on the size of the U-turning vehicle. An equation is suggested to calculate the conflicting traffic based on the composition of U-turning traffic. The conflicting traffic on six-lane roads is found to be relatively, low but on four-lane roads, almost all of the opposing traffic becomes conflicting traffic for U-turns.

Analysis and application of two-fluid model for mixed traffic conditions

Two-fluid model quantifies traffic performance on a network by studying the interaction between moving and stopped vehicles in the traffic stream. The broad objective of this study is to investigate the presence and possible impact of measurement and modeling errors (non-ergodicity and endogeneity) on two-fluid model estimates under mixed traffic conditions. This objective is pursued based on travel time and running time data obtained from six-lane roads in Chennai city. To address non-ergodicity, a suitable temporal disaggregation scheme is proposed. An orthogonal regression model is applied that accounts for measurement errors in running times and trip times. To handle endogeneity, omitted variable bias correction is applied by adding two variables. The proposed non-ergodic model, correcting for both measurement error and endogeneity, provides a better fit and more accurate estimates than conventional model. These measurement and modeling errors also affect critical traffic flow parameters and level of service benchmarks.

India: The Temple Sites at Telkupi (“Bhairavasthan”) / Rama Setu and Setusamudram Project, Protest against Channel Passage through Adam’s Bridge / Successful protest against six-lane road proposed close to Humayun’s Tomb in New Delhi

India: The Temple Sites at Telkupi (“Bhairavasthan”) / Rama Setu and Setusamudram Project, Protest against Channel Passage through Adam’s Bridge / Successful protest against six-lane road proposed close to Humayun’s Tomb in New Delhi

An Experimental Study on Lateral Acceleration of Cars in Different Environments in Sichuan, Southwest China

In view of the tremendous improvements in the dynamic performance of automobiles and changes in the composition of drivers over the past several decades, it is valuable to examine the distribution of automobile’s lateral acceleration in new environments. The lateral accelerations, speeds, and trajectory curvatures of a passenger car on twelve highways with different design speeds and topographies were obtained. By synchronizing, matching, and counting, the distribution of the lateral acceleration was obtained, and the level of driving comfort was estimated. The10th,15th,50th,85th, and90thpercentile values of the lateral acceleration on three road types (six-lane road, four-lane road, and two-lane road) were found. Combined with scatter diagrams of the lateral acceleration over the curvature, the negative correlation between the lateral acceleration and the curvature was analyzed and interpreted. In addition, regression models of the lateral acceleration with the curvature for the three kinds of roads were established. Based on scatter diagrams of the lateral acceleration over the speed, regression models of the averageaydepending on the speed and the85thpercentileaydepending on the speed of passenger cars and buses were established. The research provides calculation parameters and a control basis for operating speed prediction, pavement material design, and maximum and minimum limit value determination for the superelevation ratios and curve radii.

Adapting to suburbia: bird ecology on an urban-bushland interface in Perth, Western Australia.

Birds in urban landscapes must contend with fragmented and degraded remnants of native vegetation and their survival may be dependent on factors such as their ability to disperse through and/or utilize the urban matrix. We examined the frequency of occurrence of birds in native bushland in Kings Park, Perth, Western Australia, and in nine adjacent suburban gardens. We quantified dispersal capacity by observing bird crossing frequency and height over a major six-lane road separating the bushland from adjacent gardens. Finally we quantified matrix utilisation by recording foraging behaviour in urban gardens and bushland. Native bushland had a higher species richness than urban gardens (30 versus 17 species) and 18 species were associated more strongly with bushland. Of these 18 species, 61% were never recorded in urban gardens. Gardens were typified by three generalist species, the Singing Honeyeater Lichenostomus virescens and the introduced Laughing Dove Spilopelia senegalensis and Spotted Dove S. chinensis. Three generalist species, the Red Wattlebird Anthochaera carunculata, Rainbow Lorikeet Trichoglossus haematodus, and Brown Honeyeater Lichmera indistincta were equally abundant in all habitats. Four of 18 bird species (Singing Honeyeater Red Wattlebird, Rainbow Lorikeet, and Australian Ringneck Barnardius zonarius) accounted for the majority of road crossing events. Urban gardens provided a rich resource for generalists and urban exploiters, all of which spent significantly more time foraging on nectar in gardens and significantly more time foraging on insects in bushland. We conclude that urban gardens provide habitat for some species that exploit nectar, but most species in bushland, particularly insectivores, do not use gardens. Our results indicate the importance of retaining well-managed bushland for supporting viable urban bird populations.

Walking between the Lines: Nonvisual Cues for Maintaining Headings during Street Crossings

Five cues were evaluated with respect to their usefulness in directing the headings of pedestrians who were blind during street crossings. The study was conducted at a simulated crosswalk, with the angle of the crosswalk varied relative to the approach and direction of the slope of the ramp. Three cues worked well over the distance equivalent to the width of a six-lane road.

Analysis of Traffic and Meteorology on Airborne Particulate Matter in Münster, Northwest Germany

The importance of street traffic and meteorological conditions on the concentrations of particulate matter (PM) with an aerodynamic diameter smaller than 10 μm (PM10) was studied in the city of Münster in northwest Germany. The database consisted of meteorological data, data of PM10 mass concentrations and fine particle number (6–225 nm diameter) concentrations, and traffic intensity data as counted with tally hand counters at a four- to six-lane road. On working days, a significant correlation could be found between the diurnal mean PM10 mass concentration and vehicle number. The lower number of heavy-duty vehicles compared with passenger cars contributed more to the particle number concentration on working days than on weekend days. On weekends, when the vehicle number was very low, the correlation between PM10 mass concentration and vehicle number changed completely. Other sources of PM and the meteorology dominated the PM concentration. Independent of the weekday, by decreasing the traffic by approximately 99% during late-night hours, the PM10 concentration was reduced by 12% of the daily mean value. A correlation between PM10 and the particle number concentration was found for each weekday. In this study, meteorological parameters, including the atmospheric stability of the boundary layer, were also accounted for. The authors deployed artificial neural networks to achieve more information on the influence of various meteorological parameters, traffic, and the day of the week. A multilayer perceptron network showed the best results for predicting the PM10 concentration, with the correlation coefficient being 0.72. The influence of relative humidity, temperature, and wind was strong, whereas the influence of atmospheric stability and the traffic parameters was weak. Although traffic contributes a constant amount of particles in a daily and weekly cycle, it is the meteorology that drives most of the variability.

Second Thane Creek Road Bridge, India

Rapid development in and around New Mumbai (Bombay) has led to considerable increases in traffic, well in excess of the capacities of many existing bridges. After examining various alternatives, the State Government decided to construct a new six-lane road bridge 40 m from the existing Thane Creek Road Bridge.The Second Thane Creek Road Bridge spans the tidal creek with a total length of 1,837 m and a width of 25.7 m. It carries two carriageways a median verge and two pedestrian walkways. The bridge has a total of 23 spans, with two navigational spans, each 107 m long at a height of 9 m above average high tide.

Mathematics Investigator

Having heard on a TV ad there were more than four million miles of road in America, Doug and Nancy Abby decided one day to drive them all. In the interest of economy, convenience, and comfort, they rented a car from Alamo. Averaging 350 miles a day, on six-lane roads, one-lane roads, and all the roads in between, the Abbys stopped only to eat, sleep,…, and have a son, Robert,…, and later, a daughter, Catherine.