Urban Travel Time Research Articles

URBAN TRAVEL TIME PREDICTION BASED ON QUEUE ESTIMATION

Since delays caused by waiting in queues at intersections are main components of travel time in urban areas, this paper proposes a state space approach to predict urban travel times based on queues estimation. This approach addresses specifically the time lag between travel times as predicted at the departure and travel time as measured at the arrival travel times. An empirical data set collected from an urban street in Holland is used. The results show a promising performance on urban travel time prediction.

Modeling Urban Link Travel Time with Inductive Loop Detector Data by Using the k-NN Method

The need to measure urban link travel time (ULTT) is becoming increasingly important for network management and traveler information provision. This paper proposes the use of the k nearest neighbors ( k-NN) technique to estimate ULTT with the use of single loop inductive loop detector (ILD) data. Real-world data from London is used. This paper explores the sensitivity of travel time estimates to various k-NN design parameters. It finds that the k-NN method is not particularly sensitive to the distance metric, although care must be taken in selecting the right combination of local estimation method (LEM) and value of k. A robust LEM should be used. The optimized k-NN model is found to provide more accurate estimates than other ULTT methods. To obtain a more accurate estimate of ULTT, a potential application of this approach could be to aggregate GPS probe vehicle ULTT records from different times but the same underlying travel time distribution.

Modeling Urban Link Travel Time with Inductive Loop Detector Data by Using the k-NN Method

The need to measure urban link travel time (ULTT) is becoming increasingly important for network management and traveler infor mation provision. This paper proposes the use of the k nearest neigh bors (k-NN) technique to estimate ULTT with the use of single loop inductive loop detector (ILD) data. Real-world data from London is used. This paper explores the sensitivity of travel time estimates to var ious k-NN design parameters. It finds that the k-NN method is not particularly sensitive to the distance metric, although care must be taken in selecting the right combination of local estimation method (LEM) and value of k. A robust LEM should be used. The optimized k-NN model is found to provide more accurate estimates than other ULTT methods. To obtain a more accurate estimate of ULTT, a potential application of this approach could be to aggregate GPS probe vehicle ULTT records from different times but the same underlying travel time distribution.

Urban environment and travel times to work

The increasingly long time spent on daily travels to work causes heavy economic and non-economic losses in many cities worldwide. Possible determinants of the length of urban trips to work can be found at different levels of spatial focus, based on demographic, socioeconomic, and transport infrastructure characteristics. Following a brief review of two broad hypotheses, the paper discusses theoretical fundamentals and results of alternative duration models applied to average work travel times across 92 cities in 66 countries. Estimates are fairly robust to sample size and specification of the hazard rate. Relatively smaller and /or wealthier cities tend to have higher hazard ratios, thus implying reduced average time spent in work trips. In two out of five parametric models, the shape of the hazard function is non-monotonic, with duration dependence changing from positive into mildly negative at a long spell stage. This outcome may be interpreted as a sign of possible 'stickiness' of travel time beyond a certain threshold of high urban congestion.

Urban travel time models: a case study of Vancouver (BC)

Travel time survey data obtained from the City of Vancouver's Engineering Department show that travel times in the city have remained fairly constant over the past three decades, although traffic volumes and the number of traffic control devices have increased. This constant travel time pattern is contrary to that predicted by traditional travel time models. The traditional travel time models generally forecast travel time to increase with increasing traffic volume. This paper investigates the reasons for the observed travel time trends in Vancouver. It also investigates the validity of some traditional travel time models, by fitting the models with data collected on a few arterial streets. The results from the research indicates that the observed travel time trends are principally due to increases in vehicle speeds and increases in the capacity of the street network. Also, revised forms of the traditional travel time models have been derived for the arterial streets in the City of Vancouver.

Selecting routes to minimize urban travel time

Urban regions contain a hierarchy of roadways, ranging from a dense network of low speed local roadways to sparser networks of higher speed roadways. Because minimizing travel time is usually more important than minimizing travel distance, vehicles may detour from the route of shortest distance to gain access to higher speed roadways. This paper uses continuous space models to analyze several urban travel decisions in which a driver must select between the shortest route on relatively low speed roadways and a longer route which includes travel on higher speed roadways. Results are presented graphically for deciding when to detour to faster roadways. Parallel and intersecting high speed roadways and limited access highways are considered.

Estimating origin‐destination matrices from link volume counts: a simple intercity auto travel demand model for Sri Lanka

The cost of nation wide travel surveys is high. Hence in many developing countries, planners have found it difficult to develop intercity transportation plans due to the non availability of origin‐destination trip matrices. This paper will describe a method for the intercity auto travel estimation for Sri Lanka with link traffic volume data. The paper outlines the rationale of selecting the district capitals of Sri Lanka as its “cities,” the methodology for selecting the intercity road network, determination of link travel times from express bus schedules and the location of link volume counting positions. Initially, the total auto travel demand model is formulated with various trip purpose sub‐models. This model is finally modified to a simple demand model with district urban population and travel times between city pairs as the exogenous variables, to overcome statistical estimation difficulties. The final demand model has statistics within the acceptable regions. The advantages of a simple model are di...

Estimating urban travel times: A comparative study

This paper develops estimating equations for urban travel times. It extends Kolesar's work on urban travel times of emergency fire engine units. Multiple regression and piecewise least-squares curve fit analysis yield useful equations for predicting travel time between any two points within an urban area for automobiles and large trucks. Comparisons on real world data indicate that the simple equations yield significantly better results than those derived from standard Federal Highway Administration software.