GPS Vehicle Tracking in Urban Areas (original) (raw)

Speed Characteristics and Safety on Low Speed Urban Midblock Sections Based on GPS-Equipped Vehicle Data

Numerous studies identify potential relationships between speed characteristics and roadway safety. More specifically, the risk of crash involvement may be positively correlated with speed variation and higher vehicle speeds are generally correlated with increased crash severity. Most previous studies rely on spot speed studies, using automated traffic counters or laser/radar guns at specific points on transportation facilities, assuming that spot speed measurements and laser speed profiles can be considered representative of roadway operating speeds. However, spot speed studies cannot capture the speed profile of each individual along the entire route or driver/vehicle characteristics that may contribute to crash frequency. This paper uses GPS-equipped vehicle data obtained from the Commute Atlanta instrumented vehicle program to measure operating speed characteristics on urban streets in Atlanta, GA. The authors examine the relationship between the 85 th percentile of monitored sp...

Estimation of Travel Time in Urban Streets Using Various Modes

Travel time reliability is one of the most understood measures for road users to perceive the current traffic conditions. It helps them to make smart decisions on route choices so as to avoid unnecessary delays. Travel time information to travelers always helps to better manage trips. It helps in making various decisions, such as: route choice, departure time choice etc. and helps to reduce traffic congestion and travel delay. Establishing a relationship between travel times of various modes is always a better solution. The objective of this study is to find out a statistical relationship between public transit and private cars and vice versa. Travel time data of sections of the study routes were collected using GPS and this information was used for representing the present traffic situation. Linear regression models were developed to predict travel times of modes, one with respect to another and travel time measures were validated.

Urban Traffic Speed Management: The Use of GPS/GIS

1977

The prevailing traffic speed at any section of a roadway affects the quality of traffic at the time. Whereas excessive speeds affect the severity of road traffic accidents, crawling speeds in the urban environment is also indicative of congestion. One of the key elements in speed management planning is the functional classification of roads by speed. For example, 30km/h has been designated for residential areas and 60km/h and above for major arterial roads. Nowadays, efficient vehicle monitoring can be achieved by integrating Global Positioning System (GPS) derived traffic data such as vehicle speed and direction of traffic flow into a Geographical Information System (GIS) environment. This GPS-GIS integrated system provides real-time meaningful location and status of the vehicles in the network. The system has been used to show the second-to-second positional changes in speed and directions of vehicles travelling in Kumasi, the second largest city in Ghana. Using the geographic components in a dataset and visualizing the results in a map provided a clearer picture of the traffic-state of every route in the network. The GPS has clearly indicated the road sections where speeds are unacceptable and driver behaviour is affected giving transport planners the option to choose the desired speed management technique to improve the traffic system.

GIS and GPS to Evaluate Urban Arterial Performance

Jordan Journal of Civil Engineering, 2016

New performance-based design procedures with the incorporation of operating speeds were proposed utilizing Global Positioning System (GPS) and Geographic Information System (GIS) technologies for arterial performance evaluation and congestion quantification at urban areas. The relevance of geometrical variables and land use to operating speed was also investigated using consistency measure. The collected variables in the database layers of GIS included: traffic volume, pedestrian volume, parking occupancy rate, cross-section characteristics, geometry of road, road environment features and land use for arterials and relevant intersection layers. The results showed that: 1) Consistency could provide a new performance measure of urban streets utilizing GPS data incorporated with GIS capability; 2) Divided ring road arterials which have more length, more than one lane and are located at residential areas were more consistent with their posted speed limits than the others; 3) Congestion can be quantified using a new scheme proposed in this research work utilizing GIS and the second-by-second GPS data.

Travel Time Estimation on Urban Street Segment

PROMET - Traffic&Transportation, 2018

Level of service (LOS) is used as the main indicator of transport quality on urban roads and it is estimated based on the travel speed. The main objective of this study is to determine which of the existing models for travel speed calculation is most suitable for local conditions. The study uses actual data gathered in travel time survey on urban streets, recorded by applying second by second GPS data. The survey is limited to traffic flow in saturated conditions. The RMSE method (Root Mean Square Error) is used for research results comparison with relevant models: Akcelik, HCM (Highway Capacity Manual), Singapore model and modified BPR (the Bureau of Public Roads) function (Dowling - Skabardonis). The lowest deviation in local conditions for urban streets with standardized intersection distance (400-500 m) is demonstrated by Akcelik model. However, for streets with lower signal density (<1 signal/km) the correlation between speed and degree of saturation is best presented by HCM...

Simple Method of Predicting: Travel Speed on Urban Arterial Streets for Planning Applications

… Record: Journal of the …, 2006

Travel speed is a key measure of effectiveness for evaluating urban arterials. The Highway Capacity Manual (HCM) methodology of predicting speeds along urban streets requires complex calculations and input not typically available in long-range planning, thereby requiring the use of default values. This paper demonstrates that a simple and practical method of estimating travel speed along urban arterial streets is possible. We propose an equation derived from the HCM delay formula and calibrated with the results obtained from CORSIM-a micro-simulation model. The equation requires neither signal characteristics nor detailed traffic and geometry information about arterial intersections. The proposed model of travel speed along urban arterials uses only input available to planners. The model is evaluated with the results obtained from a field study in Lafayette, Indiana. Despite its limited scope of input and simple structure, the model properly replicates the trends found in the field. The model overestimates the actual speeds by 18 %, and a simple adjustment factor removes the bias.

SPEED ANALYSIS ON URBAN ROADS

Speed analysis on urban roads sections start from need tied up to traffic assignment models in urban networks: to calculate the average running time in a road section it is necessary to have a good evaluation of average running speed for that road section. First experimentations for the study of drivers «realized» speed (for rural roads) have been published already in 1988. In 1997 it has been published a first expression for «realized» speed in function of curvature (1/R) and of absolute value of the longitudinal road gradient for some typologies of common rural roads.

Using GPS to Measure Traffic System Performance

Computer-Aided Civil and Infrastructure Engineering, 1999

Traffic system performance can be measured in various ways, but from the user perspective, congestion is the major criterion. This article examines some novel uses of GPS in the measurement of vehicle speeds and travel times and their synthesis into measures of congestion and ultimately of the performance of the urban road system. The article also will discuss the integration of GPS-based congestion measures into an ITS framework, techniques for implementing a congestion-monitoring system, and implications for urban road system planners, managers, and users.

Profile-speed data-based models to estimate operating speeds for urban residential streets with a 30km/h speed limit

IATSS Research, 2013

A speed limit of 30 kilometres per hour (km/h) has been widely introduced for urban residential streets to ensure traffic safety and allow these streets to fulfil other intended functions. However, excessive speeds on these roads are very common, causing traffic safety problems and threatening the liveability of neighbourhoods. An effective and active way to deal with speeding is the application of a performance-based design approach, as mentioned in previous research. In a performance-based design approach, street geometrics and roadside elements are selected based on their influence on the desired driving speeds. The relationship between driving speeds and street features therefore needs to be determined. Although several studies have developed operating speed models for urban streets, all of these models were calibrated based on data for streets with speed limits of more than 30 km/h. The present research is designed to investigate the influence of various roadway and roadside characteristics on operating speeds on urban tangent street sections with a 30 km/h speed limit using profile-speed data. A simultaneous equation regression with a three-stage-least-square (3SLS) estimator was used for the modelling effort. The driving speed models developed in this study incorporate several street design factors, which provide helpful information for urban planners and street designers to cope with speeding issues on residential streets.

Arterial Speed Studies Based on Data from GPS Equipped Probe Vehicle

Journal of the Eastern Asia Society for Transportation Studies, 2015

Due to more complicated behavior than controlled access roadway, congested estimation on arterial road network has become a challenging topic for all traffic professionals in recent years. To indicate the traffic condition, link travel speed is considered as one of the important markers for representing traffic status on roadway network and most understood pointer for all road users. This paper describes the implementation of Running Speed and Stopped Delay (RSSD) technique for investigating the urban link travel speed and discusses on the limitation of error in speed associated from each global positioning system (GPS) device to maintain the advantages of proposed technique in travel speed estimation. The results from real observation traffic data on urban roadway also confirm that the accuracy of travel speed estimation is significantly improved when RSSD was employed as the estimation technique compared to baseline approach particularly in the links with highly congested condition.