scholarly journals The Impact of Emergency Parking Bays on Quasi-Eight-Lane Expressway Traffic Operations

2020 ◽  
Vol 12 (8) ◽  
pp. 3432
Author(s):  
Zhen Yang ◽  
Xiaocan Chen ◽  
Dazhi Sun
Keyword(s):  
High Volume ◽  
Traffic Volume ◽  
Simulation Software ◽  
Traffic Operations ◽  
Microscopic Simulation ◽  
Lane Changing ◽  
Traffic Demand ◽  
The Road ◽  
Traffic Operation ◽  
The Impact

Recently, with the discrepancy between increasing traffic demand and limited land resources, more and more expressways are choosing to use hard shoulders to expand into quasi-six-lane or quasi-eight-lane roads. Therefore, more emergency parking bays are used in place of traditional parking belts. However, there are no standards defining clear and unified specifications for the design of parking bays. This paper aimed to investigate the impact of emergency parking bays on expressway traffic operations with various traffic volumes and setting conditions. Based on the Monte Carlo method, VISSIM (Verkehr in Städten Simulation, a microscopic simulation software) simulation experiments were conducted using measured traffic operation data from one expressway in Zhejiang province. The probability of unsafe deceleration, lane-changing maneuvers and delay times were considered as the safety and efficiency indexes in this simulation study. The simulation results indicated that the emergency parking vehicle had an increasing impact on the following vehicle as the traffic volume increased. However, the impact pattern was found to be insensitive to the changing of the bay taper length. For low traffic volume, compared with the arrival vehicle, the departure vehicle had more impact on the traffic operation of the mainline. However, the impact of the arrival vehicle became more remarkable as the traffic volume increased. After parking, the waiting time for merging into the mainline was reduced as the volume decreased or as the bay taper increased. Furthermore, reductions caused by varying bay tapers were more significant under high volume conditions. Finally, this study suggests that parking bays are inapplicable when the occupancy of the road space exceeds 20% (about 3000 veh/h), because they would cause significant impact on the safety and efficiency of the expressway. The results of this paper are useful for the design and implementation of emergency parking bays.

scholarly journals Extracting Road Traffic Volume in the City before and during covid-19 through Video Remote Sensing

2021 ◽  
Vol 13 (12) ◽  
pp. 2329
Author(s):  
Elżbieta Macioszek ◽  
Agata Kurek
Keyword(s):  
Travel Behavior ◽  
Traffic Management ◽  
Road Traffic ◽  
Traffic Volume ◽  
The Road ◽  
Traffic Characteristics ◽  
Annual Average Daily Traffic ◽  
On The Road ◽  
The Impact ◽  
The City

Continuous, automatic measurements of road traffic volume allow the obtaining of information on daily, weekly or seasonal fluctuations in road traffic volume. They are the basis for calculating the annual average daily traffic volume, obtaining information about the relevant traffic volume, or calculating indicators for converting traffic volume from short-term measurements to average daily traffic volume. The covid-19 pandemic has contributed to extensive social and economic anomalies worldwide. In addition to the health consequences, the impact on travel behavior on the transport network was also sudden, extensive, and unpredictable. Changes in the transport behavior resulted in different values of traffic volume on the road and street network than before. The article presents road traffic volume analysis in the city before and during the restrictions related to covid-19. Selected traffic characteristics were compared for 2019 and 2020. This analysis made it possible to characterize the daily, weekly and annual variability of traffic volume in 2019 and 2020. Moreover, the article attempts to estimate daily traffic patterns at particular stages of the pandemic. These types of patterns were also constructed for the weeks in 2019 corresponding to these stages of the pandemic. Daily traffic volume distributions in 2020 were compared with the corresponding ones in 2019. The obtained results may be useful in terms of planning operational and strategic activities in the field of traffic management in the city and management in subsequent stages of a pandemic or subsequent pandemics.

Validation of Generalized Delay Model for Oversaturated Conditions

1997 ◽  
Vol 1572 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Roelof J. Engelbrecht ◽  
Daniel B. Fambro ◽  
Nagui M. Rouphail ◽  
Aladdin A. Barkawi
Keyword(s):  
Simulation Model ◽  
Close Agreement ◽  
Signalized Intersections ◽  
Delay Model ◽  
Traffic Operations ◽  
Microscopic Simulation ◽  
Highway Capacity ◽  
Traffic Demand ◽  
Highway Capacity Manual ◽  
The U.S

With today’s ever-increasing traffic demand, more and more signalized intersections are experiencing congestion for longer periods of time. To better quantify oversaturated conditions, it is necessary to accurately estimate oversaturation delay. The generalized delay model, proposed for inclusion in the next update of the U.S. Highway Capacity Manual (HCM), is introduced here. The generalized delay model differs from the model in the 1994 edition of the HCM as it is sensitive to the duration of the analysis period and is not restricted to degrees of saturation less than 1.2. The TRAF-NETSIM microscopic simulation model was used to verify the generalized delay equation for oversaturated conditions. A simulation model was used, because it is extremely difficult to measure oversaturated delay in the field. The study was designed to cover as much of the domain of oversaturated traffic operations as possible. The variability in simulated delays was investigated, and an equation was developed to predict the standard deviation of oversaturated delay estimates. It was found that delays estimated by the proposed generalized delay model are in close agreement with those simulated by TRAF-NETSIM. On average, simulated delays are overestimated slightly, but the error is small compared with actual delays. The proposed generalized delay model is expected to provide a good estimate of actual oversaturation delays that occur in the field.

scholarly journals Analysis of the influence on expressway safety of ramps

2017 ◽  
Vol 43 (3) ◽  
pp. 43-51 ◽  
Author(s):  
Juan Juan Hu ◽  
Feng Li ◽  
Bing Han ◽  
Jinbao Yao
Keyword(s):  
Traffic Safety ◽  
Traffic Volume ◽  
Delay Model ◽  
Safety Index ◽  
Traffic State ◽  
Model Based ◽  
Traffic Operation ◽  
The Impact ◽  
Location Design

As the very important parts of the expressway system, on and off ramps have a great effect on the operation effect of expressways. Once congestion occurs at on and off ramps, it will directly affect the safety of the expressway and vehicles. So this paper first analyzes the location design of on ramps, the length and the influences on the expressway running state of off ramp downstream traffic state, and establishes the expressway operation models based at on and off ramps. The expressway operation models include off ramp delay model, on ramp delay model, expressway delay model and side road delay model under the influence of the distance between on and off ramp and traffic volume. At the same time, the paper analyzes the connection between the traffic operation state and traffic safety, and establishes the expressway safety model based on congestion degree. Through simulation verification, the impact of on and off ramp on the security of the expressway is analyzed. In the simulation, safety rank division is simulated to verify and safety index of different safety ranks. Finally the paper concludes that the delay caused by traffic of the on and off ramps can decrease the safety of expressway.

scholarly journals Multi-lane Changing Model with Coupling Driving Intention and Inclination

2017 ◽  
Vol 29 (2) ◽  
pp. 185-192 ◽  
Author(s):  
Jiangfeng Wang ◽  
Chang Gao ◽  
Zhouyuan Zhu ◽  
Xuedong Yan
Keyword(s):  
Risk Factor ◽  
Lane Changing ◽  
Traffic Demand ◽  
Average Speed ◽  
Slowing Down ◽  
Behavioural Characteristics ◽  
Proposed Model ◽  
Density Flow ◽  
The Impact ◽  
The Relationship

Considering the impact of drivers’ psychology and behaviour, a multi-lane changing model coupling driving intention and inclination is proposed by introducing two quantitative indices of intention: strength of lane changing and risk factor. According to the psychological and behavioural characteristics of aggressive drivers and conservative drivers, the safety conditions for lane changing are designed respectively. The numerical simulations show that the proposed model is suitable for describing the traffic flow with frequent lane changing, which is more consistent with the driving behaviour of drivers in China. Compared with symmetric two-lane cellular automata (STCA) model, the proposed model can improve the average speed of vehicles by 1.04% under different traffic demands when aggressive drivers are in a higher proportion (the threshold of risk factor is 0.4). When the risk factor increases, the average speed shows the polarization phenomenon with the average speed slowing down in big traffic demand. The proposed model can reflect the relationship among density, flow, and speed, and the risk factor has a significant impact on density and flow.

scholarly journals The use of a simulation model to analyze the impact of heavy transport generated by the port to the city traffic.

2017 ◽  
Vol 42 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Natalia Stasiak ◽  
Leszek Smolarek
Keyword(s):  
Average Length ◽  
Autonomous Vehicle ◽  
Urban Traffic ◽  
Microscopic Simulation ◽  
Traffic Lights ◽  
The Road ◽  
Time Of Travel ◽  
The Impact ◽  
The City ◽  
The Web

Abstract The article presents an analysis of the impact of transport on heavy urban traffic on Wharf Kwiatkowski using program PTV Vissim. The data for analysis were taken from the Road and Greenery in Gdynia from program PTV Visum. Attention has been focused on vehicle traffic in the afternoon the top of its intensity. Model of Kwiatkowskiego Wharf, made entirely in the PTV VISSIM, was used for microscopic simulation of traffic. With its help, it was possible to find and analyze the behavior of each autonomous vehicle and interactions on the Web. For the analysis was used as a program of traffic lights currency at these junctions. The analysis results of simulation in the PTV VISSIM are related to the movement of the two structures. The first assumes that the route will move cars and trucks, taking into account their share in the network based on the intensity of traffic during peak hours of the afternoon, the second consisted only of cars. The results presented are based on measuring the time of travel and delays on specific relationships and the average length of queues at selected inlets. The results of analysis and simulation tests were subjected to statistical analysis.

scholarly journals Capacity Estimation of On-Street, Mid-Block, Off-Line Bus Stops Considering Yield-to-Bus Rule

2019 ◽  
Vol 2673 (1) ◽  
pp. 269-278 ◽  
Author(s):  
Faheema Hisham ◽  
Jonathan M. Bunker ◽  
Ashish Bhaskar
Keyword(s):  
Traffic Volume ◽  
Microscopic Simulation ◽  
Additional Time ◽  
Bus Stop ◽  
Traffic Capacity ◽  
Transit Capacity ◽  
Bus Stops ◽  
Time Required ◽  
The Impact

The effectiveness of an on-street bus facility depends on the volume of general traffic sharing the buses’ travel lane. The Transit Capacity and Quality of Service Manual (TCQSM) methodology estimates capacity of a bus facility based on the operation of critical stops. The aim of this study is to understand better the performance of an on-street, mid-block, off-line bus stop by relating bus stop capacity to adjacent lane traffic volume. The contributions of this paper are twofold. First, the TCQSM methodology incorporates the effect of adjacent lane traffic volume on bus stop capacity at mid-block bus stops through its effect on re-entry delay, but it does not consider the impact of the bus stop itself on adjacent lane traffic capacity. This paper introduces a novel methodology to estimate the additional time required to accommodate adjacent lane traffic volume under saturated conditions. Second, the TCQSM methodology does not reflect the effect on re-entry delay of a yield-to-bus (YTB) rule, which is mandatory by law in some jurisdictions. This paper modifies the current TCQSM methodology by allowing for the YTB rule. A microscopic simulation model is developed in order to cross-validate the theoretical model developed.

Evaluation of Signalized Intersection Service Level in the Traffic Impact Assessment

2013 ◽  
Vol 869-870 ◽  
pp. 327-333
Author(s):  
Qian Wang ◽  
Chun Fu Shao
Keyword(s):  
Impact Assessment ◽  
Traffic Flow ◽  
Service Level ◽  
Signalized Intersection ◽  
Traffic Demand ◽  
The Road ◽  
Traffic Impact ◽  
On The Road ◽  
Vehicle Capacity ◽  
The Impact

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.

scholarly journals Incorporating Driver Relaxation into Factory Adaptive Cruise Control and its Implications on Traffic Operation

2021 ◽  
Author(s):  
Hao Zhou ◽  
Jorge Laval
Keyword(s):  
Adaptive Cruise Control ◽  
Smooth Transition ◽  
Vehicle Speed ◽  
Cruise Control ◽  
Lane Changing ◽  
Speed Reduction ◽  
Time Headway ◽  
Traffic Operation ◽  
The Impact ◽  
Lateral Propagation

Current adaptive cruise control (ACC) systems adopt fixed desired time headway, which leads to an abrupt speed reduction after being cut-in by a lane changer in front or when changing lanes too close to the new leader. In contrast, human drivers behave differently and feature a variable spacing within 20 or 30 seconds right after a cut-in or lane change. Motivated by the smooth transition found in driver relaxation, the paper aims to incorporate relaxation into ACC systems. Based on the open-source ACC platform, Openpilot, Comma.ai, the paper proposes a feasible relaxation model compatible with current factory ACCs, which has also been tested using a market car with stock ACC hardware. The study further investigates the impact of relaxation ACC on traffic operation. Numerical simulation suggests that incorporating relaxation into ACC can help: i) reduce the magnitude of speed perturbations in both cut-in vehicles and followers; ii) stabilize the lane-changing traffic by reducing the speed variance and prevent the lateral propagation of congestion, and iii) increase the average vehicle speed and capacity in merging traffic.

A Capacity Estimation Model for a Contraflow Left-Turn Pocket Lane at Signalized Intersections

2018 ◽  
Vol 2672 (17) ◽  
pp. 22-34 ◽  
Author(s):  
Yi Zhao ◽  
Rachel M. James ◽  
Lin Xiao ◽  
Joe Bared
Keyword(s):  
Signalized Intersections ◽  
Signalized Intersection ◽  
Traffic Operations ◽  
Estimation Model ◽  
Capacity Estimation ◽  
Average Delay ◽  
Left Turn ◽  
Traffic Demand ◽  
Key Characteristics ◽  
The Impact

Alternative intersection designs are increasingly proposed and adopted by different agencies to meet the needs of growing traffic demand and constrained transportation resources. The left turn (LT) is one of the most critical movements at signalized intersections from both a safety and operations perspective. Heavy LT volumes are especially impactful to the operational efficiency of a signalized intersection and often result in queue spillback. A contraflow left-turn pocket lane (CLPL) is proposed to mitigate congestion caused by heavy LT demand and has been shown in simulation to greatly mitigate the impact of queue spillback. The CLPL dynamically uses the opposing through lane (OTL) as an additional LT lane within the signal cycle on a temporary basis when the OTL is not occupied by through traffic. While geometric design schematics and analytical procedures for estimating delay have been proposed and discussed in existing literature, methodologies for estimating capacity benefits and traffic operations are not yet well defined. This paper has three primary contributions to the literature: development of a probabilistic capacity estimation model, exploration of the impact of key characteristics (e.g., cycle length, LT demand, lane selection preference) on estimated intersection capacity, and recommendations for the real-world implementation of a CLPL. The simulation results indicate that the CLPL treatment can increase a signalized intersection’s throughput up to 25% and decrease the intersection’s average delay by 35%.

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