Fastlane: New Multiclass First-Order Traffic Flow Model

The heterogeneity of traffic is a significant if not dominant factor in accurately modeling freeway traffic flow operations. For example, high truck percentages may induce congestion at much lower volumes, and hence different network traffic conditions may result than with low truck percentages. This implies that traffic models for real-time decision support systems in traffic management centers should provide the means to account for traffic heterogeneity. A new, multiclass, first-order traffic model is presented that provides these means and is implemented in the decision-support system BOSS-Offline, operational in all five highway traffic management centers in the Netherlands. FASTLANE differs from earlier multiclass first-order macroscopic traffic models in that it calculates the dynamics in terms of state-dependent (instead of constant) passenger-car equivalents, which is in line with both theory and empirical microscopic data. The model is numerically solved by an efficient and stable Godunov-based solver while maintaining a dynamic and realistic representation of class-specific flows and densities throughout the network. In two synthetic test cases and one based on real data, the workings of FASTLANE under different truck percentages and different conditions are demonstrated.