Chinese postman problem with priority nodes

A generalization of the Chinese Postman Problem is studied in which the delays at a subset of priority nodes are penalized in the cost function. As it is shown that the problem is NP-hard, two tour constructing heuristics are proposed, and their properties are studied. It is proved that one of the heuristics gives optimal solutions on a subset of instances with bounded cost of delays. The implementations of the heuristics are compared on several types of randomly generated instances.