A generalized sensor location model for the estimation of network origin–destination matrices

• We model network flow observability and estimation problems using heterogeneous sensor information.
• We formulate the network O–D demand estimation problem by a link-based approach.
• Increasing active-type sensor information will improve the O–D demand estimation results.
• Network flow observability is significantly influenced by a budget constraint.

This study examined the network sensor location problem by using heterogeneous sensor information to estimate link-based network origin–destination (O–D) demands. The proposed generalized sensor location model enables different sensors’ traffic monitoring capabilities to be used efficiently and the optimal number and deployment locations of both passive- and active-type sensors to be determined simultaneously without path enumeration. The proposed sensor location model was applied to solve the network O–D demand estimation problem. One unique aspect of the proposed model and solution algorithms is that they provide satisfactory network O–D demand estimates without requiring unreasonable assumptions of known prior information on O–D demands, turning proportions, or route choice probabilities. Therefore, the proposed model and solution algorithms can be practically used in numerous offline transportation planning and online traffic operation applications.