6 research outputs found
Spatio-Temporal Dual Graph Neural Networks for Travel Time Estimation
Travel time estimation is one of the core tasks for the development of
intelligent transportation systems. Most previous works model the road segments
or intersections separately by learning their spatio-temporal characteristics
to estimate travel time. However, due to the continuous alternations of the
road segments and intersections in a path, the dynamic features are supposed to
be coupled and interactive. Therefore, modeling one of them limits further
improvement in accuracy of estimating travel time. To address the above
problems, a novel graph-based deep learning framework for travel time
estimation is proposed in this paper, namely Spatio-Temporal Dual Graph Neural
Networks (STDGNN). Specifically, we first establish the node-wise and edge-wise
graphs to respectively characterize the adjacency relations of intersections
and that of road segments. In order to extract the joint spatio-temporal
correlations of the intersections and road segments, we adopt the
spatio-temporal dual graph learning approach that incorporates multiple
spatial-temporal dual graph learning modules with multi-scale network
architectures for capturing multi-level spatial-temporal information from the
dual graph. Finally, we employ the multi-task learning approach to estimate the
travel time of a given whole route, each road segment and intersection
simultaneously. We conduct extensive experiments to evaluate our proposed model
on three real-world trajectory datasets, and the experimental results show that
STDGNN significantly outperforms several state-of-art baselines
Self supplied navigation systems: microsimulation-based performance assessment
The self-supplied navigation concept is based on the combination of the floating car data technique and the dynamic route guidance service in the same vehicles. The gains obtained by the users of such system are, obviously, closely related to the percentage of equipped vehicles. This study shows concretely this relation relying on the use of a large scale microsimulator urban model, the Lausanne city case. Finally, limitations due to the fact that the same vehicles are providing and exploiting the traffic information are clearly emphasized
Optimizing vehicle profile speed settings based on historic data
This work presents several methods for optimising speed profiles that minimise the traveltime devitations compared to historical traffic data. Defining optimisation models based at different level of detail of the reference data (segment traveltime or total trip traveltime)