Intersection Level Of Service Research Articles

Traffic Signalizing Application at Unsignalized Intersection Applying Vissim Software Microsimulation

An intersection is a meeting point of several road sections that have potential traffic conflicts. Each of these may become the intersection of opposite traffic flows. Therefore, it is critical to have the best traffic control to avoid potential collisions among vehicles. Simpang Jembatan 5 Kalimalang is an unsignalized-intersection with four legs—one of which is a bridge. The absence of traffic control in the intersection may lead to many traffic conflicts. This study aims to determine the best traffic control to increase safety in Simpang Jembatan 5 Kalimalang. It was a case study with a micro-simulation method of analysis. The data were analyzed using VISSIM and SSAM. VISSIM was used to analyze the performance of the existing intersection condition in Simpang Jembatan 5 and to analyze the counter condition for the recommendation. Meanwhile, SSAM was employed to analyze traffic conflict in the intersection. The result of the study revealed that the alternative counter condition of the intersection in terms of replenishment of two-phased-APPIL with 106 seconds of cycle time was effective in reducing 24% of traffic conflict; in addition, the delay value was 12.4 indicating that the intersection service level was down to B level. The reduction of traffic conflict and intersection service implied that the safety level in Simpang Jembatan 5 Kalimalang increased.

ANALISIS KINERJA SIMPANG KARANGLO PASCA PEMBANGUNAN UNDERPASS KARANGLO TOL MALANG – PANDAAN

Karanglo underpass construction aims to reduce traffic congestion at the Karanglo intersection due to the addition of the Malang - Pandaan Toll Road arm. Anyhow, at the end road of Karanglo Intersection causes traffic jam and long vehicle queue. Related with that problem, so it is necessary to analyze the intersection performance, alternative improvement, and vehicle operating cost at the Karanglo intersection. The data used in this analysis are primary and secondary data. Primary data are obtained from road geometric measurements and phase and signal cycle measurements, while secondary data are obtained from the Central Statistics Agency (BPS) of Malang Regency and forecasting LHR data and side barriers. For the data processing, it uses Indonesian Highway Capacity Manual (MKJI) method 1997. Vehicle operating cost uses a handbook from Ministry of Public Works Directorate General of Highways 2005. Based on the analysis’ result, the performance of the existing intersection condition obtained delay (D) = 220.12 and the intersection service level (LOS) = E. From the analysis’ result, it is needed an alternative of intersection refinement by designing the signal phase, so that the delay (D) = 21.99 and the intersection services level (LOS) = C. The Vehicle operating cost before there was underpass for light vehicle was Rp 6.143/km. The vehicle operating cost after the underpass for light vehicle was Rp. 4.979/km.

ANALISIS KINERJA SIMPANG BERSINYAL DAN BIAYA OPERASIONAL KENDARAAN PADA JALAN GALUNGGUNG – JALAN RAYA TIDAR – JALAN BONDOWOSO KOTA MALANG

Increased traffic flow at crossroads that doesn’t have a suitable infrastructure can cause traffic jam. The traffic jam that occurs also has an impact on vehicle operating cost that passing through the intersection. On the page malangchannel.com, the intersection at Jalan Galunggung, Jalan Raya Tidar and Jalan Bondowoso is one of the points in Malang City that have high frequently traffic jams. Congestion occurs because there are many motorized vehicles across to the area, where the area around the location has a shops, malls, campuses, and others. This study aims to find how much the intersection Level Of Service (LOS) and the vehicle operating costs that passing through the intersection and give the best solution in order to improve the performance of the intersection and reduce the vehicle operating cost. The data used include the geometric of intersection, traffic signals, side friction, traffic volume during peak hours, average speed of vehicles during peak hours and components of vehicle operating costs. The calculation of intersection performance using MKJI 1997, vehicle operating costs using Pacific Consultant International (PCI) and intersection congestion costs using Tzedakis 1980. The calculation results show that the existing condition of the intersection has passed the saturation point with the service level (LOS) F of and the average vehicle delay 1013.6 sec / pcu and the congestion cost Rp. 86,744,635 / hour for light vehicles (LV). and IDR 15,424,569 / hour for heavy vehicles (HV). Alternative improvements of intersection by resetting the phases from 2 to 4, road geometric adjustment and adding the flyovers, the congestion costs can be reduced to Rp. 1,319,498 / hour for light vehicles (LV) and Rp. 231,244 / hour for heavy vehicles (HV) with the Level Of Service (LOS) B from average delay of vehicle 14.5 sec / pcu.

PERFORMANCE ANALYSIS OF UNSIGNALIZED INTERSECTION ON PERJUANGAN AND VETERAN STREET MARTAPURA BANJAR DISTRICT

The intersection of Jl. Perjuangan – Jl. Veteran is located in Martapura City, Banjar Regency, South Kalimantan Province. At this intersection there are only cautionary street lights or yellow lights, then the Intersection condition which is the road to residential areas, schools, shops, and traditional markets to support the occurrence of traffic jams and accidents Primary data or data taken from the field include geometric conditions, environmental conditions, side barriers, traffic volume at the Intersection of Jalan Perjuangan - Jalan Veteran Martapura City. Secondary data includes the number of residents in Martapura City and data on the growth of the number of vehicles. Furthermore, the data samples were analyzed using the Indonesian Road Capacity Manual (MKJI, 1997) to find out whether Intersection performance is still feasible or not. If the results of the analysis show that the Intersection performance is no longer feasible, it is necessary to solve the problem. At the intersection, Jl. Perjuangan - Jl. Veteran, Martapura City, Banjar Regency, on a unsignal condition, obtained a degree of saturation (DS) of 0.76 and delay (D) of all intersections of 12.7 seconds / smp with the Service Level Index at B, which indicates that at the intersection still has good conditions. After forecasting analysis, it is found that in the 6th year the degree of saturation (DS) is 1.11 and the whole delay is 26.21 seconds / smp with the Service Level Index in class D where the intersection has reached a bad condition or must be done intersection management analysis. By analyzing the form of intersection management when applied with a signalized intersection, the alternative 2 phase proposal is the best which is seen from the degree of saturation and delay with the value of Degree Saturation (DS) 0.74 and Delay (D) 18,33 seconds / smp with the intersection service level becomes C.

Optimal signal timing design for the intersection of Dazhi Street and Hexing Road

The phenomenon of intersection congestion has become a major problem in the city. Based on the intersection of Hexing road and Dazhi street, the delay phenomenon of Urban Road intersection is optimized. The intersection of Hexing road and Dazhi street is seriously delayed. In order to improve the road capacity of the intersection and reduce the delay of the intersection, the traffic characteristics parameters of the intersection during peak period are obtained, and the traffic capacity and intersection service level of the signalized intersection are analyzed and calculated. Based on the study of the basic content and research methods of signal timing at signalized intersections, the microscopic simulation software VISSIM was used to improve the traffic control scheme with serious delays at intersections and low urban road capacity, the simulation optimization is carried out by changing the signal timing and resetting the channelization scheme of intersection. Meanwhile, the signal timing of intersection is optimized. The results show that the traffic capacity of the intersection has been greatly improved by VISSIM simulation.

Analisis Kinerja Simpang Tak Bersinyal Jalan Raya Dramaga-Bubulak Bogor, Jawa Barat

The potential of traffic problems at non-signal intersection relatively higher and more complex than signalized intersection. Intersection of Dramaga-Bubulak street has no signal and is one of the intersection with high level mobility. The research objectives were to analysis the performance of actual conditions and alternatives strategies to improve intersection performance as well as to know the influence of one way traffic system on intersection performance. The results showed that the volume of traffic passing the intersection were 3816 passenger car unit (pcu)/hour at peak hour with degree of saturation (DS) of 0.85 and delay on the intersection was 14.41 sec/pcu so the intersection service level was B. The service level of intersection was good, so the research analyzed three alternatives strategies to decrease DS value. Performance analysis of traffic showed that alternatives I was the best model alternative condition, because application of one way traffic system on outer ring Bubulak would decreased the service level of Dramaga-Bubulak street.Key words: intersection, non-signal, street

Level of Service Calculation for Four-Leg Intersection with Different Types of Priorities

Calculation of an intersection Level of Service (delay values in the intersection) is the basis for subsequent development of the area as well as testing factor for the optimum conditions of road traffic. However just as important in evaluating an intersections is the road priority direction. Bringing together the two necessities, in the current context of development, evaluation junctions also needs to be done based on delays caused by road direction priority and the possible problems it causes. A good road traffic requires a low delay value based on road direction priority.

Analysis of Traffic Operation for AL-Kafa’at Signalized Intersection in Al-Kut City

Traffic Studies Aim (Traffic analysis) to estimate some of the important indicators to determine the level of service (LOS) at intersections in the cities. That's where the increase in traffic volumes at intersections is one of the main problems that makes the traffic difficult in these intersections and which raises congestion in these areas. The objective of this research is to evaluate the operational capacity of intersection (AL-Kafa’at) in AL-Kut city and show better proposals to improve the performance in terms of capacity. To achieve these objectives traffic information has been collected using digital camera to various directions for the purposes of analysis and traffic engineering while HCS traffic program is used for the purposes of traffic analysis process. The operational analysis of the existing conditions of this intersection indicates that the LOS is (F) with an intersection delay value of 105.1 sec. /vehicle .Because of the reasons above, it is important to enhance the performance of AL-Kafa’at Intersection by increasing the number of lanes to the right turn for Alhaidariya Approach. The results indicate that the intersection LOS is hanged to (D) with a cycle time of 91 sec. and an intersection delay of 38.1 sec. /vehicle.

Simulation Based Analysis of Scramble Crossings at Signalized Intersections

This paper conducts an analysis of the effect of scramble crossings in comparison with that of normal ones on the intersection performance by using simulation models. Based on real data collected at a signalized intersection with normal crossings, the research firstly designs and simulates the scenario of scramble crossings at the studied intersection. The paper secondly analyses the effects of the scramble crossings and that of the normal ones under various situations of traffic flow and pedestrian demand. The paper results show that the scramble crossings keep the intersection level of service more stable than the normal ones once the situations of traffic and pedestrian change. In terms of vehicle delay reduction, the pedestrian demand plays an important role in the decisions of choosing the crossing type. The higher the pedestrian demand is, the more advantageous the scramble crossings are. The scramble crossings can reduce the vehicle delay significantly, by up to 35.74% compared with the normal pedestrian crossings.

Evaluation of Signalized Intersection Service Level in the Traffic Impact Assessment

Traffic Impact Assessment focuses on analysis and evaluation of the traffic flow generated by the proposed project impact on the road network in the future, through comparing the sections,intersection and other transportation infrastructure indexes such as traffic flow and road vehicle capacity, evaluate whether the traffic system can meet the increased traffic demand. In this paper, make the delay time and the road saturation as the evaluation index, studies the influence scope of the key signal intersection service level, in order to assess the impact of new projects on the signalized intersection. Cited Haikou province Hongzhou center as an example, based on the investigation of the traffic flow, calculate the time delay and road saturation to analyze the service level.

User perceptions of signalised intersection level of service using fuzzy logic

Delay has been selected as the only measure for determining signalised intersection level-of-service (LOS). Previous studies reported that road users consider multiple factors in their evaluation of LOS, including traffic-related and non-traffic factors. The findings from more than 1300 responses to a web-based stated-preference survey suggest that road users consider multiple factors for the evaluation of signalised intersections. A methodology based on fuzzy logic is presented in this article to determine the signalised intersection LOS that explicitly accounts for user perceptions. To reflect the fuzziness of user perceptions, rigid LOS thresholds were replaced with fuzzy numbers. Fuzzy inferences were applied to combine important factors at signalised intersections for deriving a composite LOS measure. A case study with different improvement scenarios was conducted to illustrate the proposed method. Overall, the fuzzy logic method simulates the human reasoning process and provides a feasible alternative to quantify the user perceptions of signalised intersection LOS.

Level of service: the politics of reconfiguring urban streets in San Francisco, CA

Intersection level of service (LOS) is a traffic engineering concept which measures how streets handle automobile traffic. It is widely used in transportation planning as an indicator of delay at intersections. The use of LOS is often criticized for its bias towards automobiles at the expense of bicycling, transit, and walking, and it complicates smart growth or compact development. In San Francisco, California, there is a political movement to eliminate the use of LOS in planning. But this movement has met significant obstacles and debate. In this paper I explore how the debate in San Francisco is unfolding and suggest implications for broader efforts to reconfigure urban streets and urban space in the United States and globally.

Prediction of User Perceptions of Signalized Intersection Level of Service Based on Fuzzy Neural Networks

Level of service (LOS) methodology incorporating user perceptions provides a measure of how well signalized intersections accommodate their users. This methodology offers new insights into signalized intersection LOS and may thus overcome the limitations of conventional delay-based methods to some extent. However, few studies on this perception-based LOS methodology have been conducted in China, where traffic conditions can be characterized by high volumes of pedestrians and bicycles. To fill the gap, this study proposes a fuzzy neural networks–based approach to predict user perceptions of signalized intersection LOS. Membership values are used to measure the perceived levels of the influential attributes that are difficult to capture accurately. A neural network containing fuzzy reasoning experiences is employed to combine the perceived attributes in order to determine LOS. To illustrate the proposed approach, a case study is performed on turning movement LOS under mixed traffic conditions. The LOS model is further calibrated and validated by using the data collected in a visualization-based survey conducted in Beijing. The numerical results indicate that the model has a favorable capability to predict user perceptions of LOS. Pearson correlation coefficients demonstrate the weak linear association between user perceptions (LOS ratings) and capacities (or volume-to-capacity ratios). Analyses of variance statistically support that users’ LOS ratings differ significantly at different levels of capacities (or volume-to-capacity ratios). The ratings depend strongly on delays. The survey results validate the delay-based method proposed by the Highway Capacity Manual to some extent.

US-36 Environmental Impact Statement and Basic Engineering: Methodology of Grade Crossing Evaluation

A study was conducted in support of the US-36 Environmental Impact Statement for the proposed commuter rail corridor between Denver and Boulder, Colorado, which determined when consideration of a grade separation may be appropriate for rail crossings in the corridor. The analysis involved three criteria: safety, vehicular travel delay, and feasibility. The methodology for evaluating crossings for grade separation is presented for agencies undertaking roadway–railroad intersection projects to consider. The analysis uses an accident prediction tool in the FRA GradeDec.NET software to assess safety risk and proposes a risk threshold. The evaluation of vehicular travel delay uses standard equations from the Highway Capacity Manual to compare estimated delay with intersection level of service and thus to define an allowable threshold for the project. This paper discusses physical, environmental, social, public, and financial feasibility to help users determine quickly whether any of these factors constitutes a fatal flaw for the analysis. The procedures described establish a methodology for planners and engineers to determine the feasibility of maintaining a roadway–railroad crossing in its existing configuration when implementing a higher-frequency service along an existing railroad corridor. With this method, planning level information may be derived and applied to perform the safety and vehicular travel delay analyses. Users may do a quick screening to eliminate crossings that can operate safely and efficiently with minimal modifications; the responsible agency can then focus time and money on areas that may present challenges to safe and efficient operations.

Potential Effects of Wet Conditions on Signalized Intersection LOS

Although rain and other precipitation is common, analyses of signalized intersections based on the Highway Capacity Manual require clear weather and dry pavement conditions. Three factors may be affected by wet weather: saturation flow, effective green time, and progression. Saturation headway may lengthen, effective green may shrink, and progression may worsen in wet conditions. As a result, signalized intersection operations become less efficient. This is demonstrated in the longer delays estimated for five sample intersections. A methodology was developed for the derivation of the probability of rainfall ( Pwet ) during the morning and evening peak hours for any intersection in the United States using readily available rainfall accumulation data from the National Oceanic and Atmospheric Administration. Once delay and level of service (LOS) are estimated for both dry and wet conditions, a weighted average is employed for estimating delays and LOS that represent the prevailing dry and wet peak period con...

Intersection Level of Service for the Bicycle Through Movement

The Florida Department of Transportation (DOT) has initiated multi-modal level-of-service (LOS) methodologies, including that for the bicycle travel mode. It has already adopted a bicycle LOS methodology for the roadway segment portion of the transportation network, the Bicycle Level of Service Model. Florida DOT’s ultimate goal is to develop corridor- and facilities-level LOS methodologies. Toward that goal, Florida DOT sponsored research to develop the first part of an intersection bicycle LOS methodology, the Intersection LOS for the bicycle through movement. This Intersection LOS for the bicycle through movement would provide a measure of the level of safety and comfort experienced by bicyclists riding through an intersection. The Intersection LOS model for the bicycle through movement is based on Pearson correlation analyses and stepwise regression modeling of approximately 1,000 combined real-time perceptions from bicyclists traveling a course through a typical U.S. metropolitan area’s signalized intersections. The study’s participants represented a cross section of age, gender, and geographic origin of the population of cyclists. Although further hypothesis testing is being conducted, the resulting general model for the Intersection LOS for the bicycle through movement is highly reliable, has a high correlation coefficient ( R2 = 0.83) with the average observations, and is transferable to the vast majority of U.S. metropolitan areas. The study reveals that roadway traffic volume, total width of the outside through lane, and the intersection (cross street) crossing distance are primary factors in the Intersection LOS for the bicycle through movement.

A New Screening Measure to Identify Potential Carbon Monoxide Hotspots

ABSTRACT To demonstrate conformity of transportation projects to National Ambient Air Quality Standards in accordance with State Implementation Plans, the U.S. Environmental Protection Agency (EPA) uses intersection level of service (LOS) as one of its major criteria for screening for potential carbon monoxide (CO) hotspots. Although intersection LOS is a measure of traffic volume, signal timing, and related congestion and delay, the assigned level reflects only the computed averaged stopped delay (ASD) per vehicle at the intersection. Thus, intersections can often operate at the same LOS but produce vastly different levels of predicted CO concentrations. For example, a two-lane approach operating at LOS D will produce very different levels of CO than a five-lane approach also operating at LOS D. This study explores the effectiveness of the LOS D criterion as a screen for identifying potential CO hotspots. The study results indicate that LOS is a poor predictor of potential CO hotspots when compared to results generated with the EPA-recommended micro-scale model CAL3QHCr. To more consistently screen out those intersections that will not be identified as CO hotspots using the micro-scale models, a new criterion, equivalent red-time vehicles (ERTV), is introduced. The modeling results using ERTV suggest that it is a more robust measure for identifying potential CO hotspots, and conversely, screening out those intersections that are not likely to be identified as hotspots using micro-scale simulation results.

Differences in causality factors for single and multi-vehicle crashes on two-lane roads

Past research has found a non-linear relationship between traffic intensity or level of service (LOS) and highway crash rates. This paper investigates this relationship further by including the effects of site characteristics and estimating Poisson regression models for predicting single and multi-vehicle crashes separately. Analysis focuses on rural two-lane highways, with hourly LOS, traffic composition, and highway geometric characteristics as independent variables. The resulting models for single and multi-vehicle crashes have different explanatory variables. Single-vehicle crash rates decrease with increasing traffic intensity (lower LOS), shoulder width and sight distance. Multi-vehicle crash rates increase with the number of signals, the daily single-unit truck percentage, and the shoulder width, and decreased on principal arterials compared to other roadway classes. LOS does not significantly explain variation in the number of multi-vehicle crashes. Ongoing research by the authors is aimed at identifying other site factors, such as driveway density and intersection LOS, that can better explain the differing effects reported here and predict crash rates of both types better.

Project Level Carbon Monoxide Hot-Spot Analysis for Level of Service D Intersections

Hot-spot [localized carbon monoxide (CO) and particulate matter (PM10) violations] analysis is often required by the Environmental Protection Agency (EPA) to determine project level air quality conformity of transportation projects in accordance with state implementation plans. EPA uses intersection level of service (LOS) as one of its major criteria for identifying potential CO hot spots. EPA’s 1992 Guideline for Modeling CO from Roadway Intersections states that hot-spot analysis is not required for those intersections operating at LOS A, B, or C (i.e., these intersections are automatically eliminated as potential CO hot spots), whereas intersections operating at LOS D or worse must undergo detailed CO concentration analysis. Of all possible LOS D intersections, clearly only a few will actually require detailed modeling of CO concentrations. A new screening methodology that introduces the concept of meteorological situation-orientated reference charts is presented. Variations on the basic reference charts can incorporate such effects as signal type (e.g., pretimed versus actuated) and future fleet characteristics. Once the desired reference charts have been developed, to use them the analyst needs only to identify the applicable reference chart on the basis of the location of the project at hand and an approximate background concentration. The proposed screening methodology should save both effort and money often wasted on the redesign of intersections that are predicted to be hot spots at the time of air quality conformity analysis and when detailed air quality analysis of LOS D intersections is undertaken for intersections that are unlikely to be CO hot spots.