The need to measure urban link travel time (ULTT) is becoming increasingly important for the purposes both of network management and traveller information provision. This paper proposes the use of the k nearest neighbors (k-NN) technique to estimate ULTT using single loop inductive loop detector (ILD) data. 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 optimised k-NN model is found to provide more accurate estimates than other ULTT methods. 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 together, to obtain a more accurate estimate of ULTT.

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There is considerable research in the literature on the dwell time of buses at bus stops. However, common measures of dwell time do not consider the time lost by the bus decelerating and accelerating from a stationary speed to serve the stop. This paper identifies eight features that are observed when a bus serves a bus stop. These features were used to propose a definition of dwell time that can be measured with bus automatic vehicle location systems. A proposed metric gives the time that would have been saved had the bus stop not been present in the road network. Metrics were calculated for all bus stops on Route 45 in London; more than 50,000 stop visit events were used for the calculation. The time lost arriving at (i.e., decelerating) and departing from (i.e., accelerating) the bus stop was typically 11.6 s. This interval was often much longer than the time lost when the doors were open at the bus stop. Buses were shown to lose significant time serving a bus stop even if the bus never came to a halt at the stop. The method proposed in this paper can be used by transit agencies to measure the actual drive time of buses, removing the component of time lost serving the bus stop. The method can be used to identify bus stops that may need redesign to reduce the time lost in arriving and departing. A novel contribution of this research is that all proposed metrics can be automatically measured with modern automatic vehicle location systems, allowing easy collection of information.

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