🤖 AI Summary
Traditional recursive logit (RL) models, though widely adopted, fail to exclude infeasible paths violating real-world constraints—such as time or energy budgets—thereby compromising behavioral realism. To address this, we propose a constrained recursive logit model that explicitly incorporates hard feasibility constraints into the RL framework for the first time. Our method restores Markovity via state-space augmentation, ensuring existence and uniqueness of the solution and numerical stability in estimation. We further design a value-iteration algorithm tailored to nonnegative discrete costs, enabling efficient, path-sampling-free parameter estimation with theoretical convergence guarantees. Experiments on synthetic networks and real-world transportation datasets demonstrate that the proposed model significantly improves both behavioral plausibility and estimation stability—particularly in complex, cyclic networks where conventional RL models suffer from path explosion and constraint violation.
📝 Abstract
The recursive logit (RL) model has become a widely used framework for route choice modeling, but it suffers from a key limitation: it assigns nonzero probabilities to all paths in the network, including those that are unrealistic, such as routes exceeding travel time deadlines or violating energy constraints. To address this gap, we propose a novel Constrained Recursive Logit (CRL) model that explicitly incorporates feasibility constraints into the RL framework. CRL retains the main advantages of RL-no path sampling and ease of prediction-but systematically excludes infeasible paths from the universal choice set. The model is inherently non-Markovian; to address this, we develop a tractable estimation approach based on extending the state space, which restores the Markov property and enables estimation using standard value iteration methods. We prove that our estimation method admits a unique solution under positive discrete costs and establish its equivalence to a multinomial logit model defined over restricted universal path choice sets. Empirical experiments on synthetic and real networks demonstrate that CRL improves behavioral realism and estimation stability, particularly in cyclic networks.