Spatiotemporal statistical features of velocity responses to traffic congestions in a local motorway network

TL;DR

This paper analyzes the spatiotemporal statistical features of velocity responses to traffic congestion in a local motorway network, revealing phase changes, power-law decay, and scaling properties in traffic dynamics.

Contribution

It introduces a novel response function and congestion indicator to empirically analyze causality and spatiotemporal features of traffic velocity responses.

Findings

Velocity responses exhibit phase changes over time.

Response decays as a power law with distance.

Scaling properties enable collapse of response functions.

Abstract

The causal connection between congestions and velocity changes at different locations induces various statistical features, which we identify and measure in detail. We carry out an empirical analysis of large-scale traffic data on a local motorway network around the Breitscheid intersection in the North Rhine-Westphalia, Germany. We put forward a response function which measures the velocity change at a certain location versus time conditioned on a congestion at another location. We use a novel definition of the corresponding congestion indicator to ensure causality. We find that the response of velocities to the congestion exhibits phase changes in time. A negative response at smaller time lags transforms into positive one at larger time lags, implying a certain traffic mechanism. The response decays as a power law with the distance. We also identify a scaling property leading to a collapse of the response functions on one curve.