Nested Markov Decision Framework for Coordinating Pavement Improvement with Capacity Expansion

Pavement improvement and capacity expansion traditionally fall in two different decision-making processes. Pavement improvement decisions are typically made at the maintenance level and focus on maintaining, rehabilitating, and reconstructing the existing pavements with respect to the physical conditions, such as poor riding quality, severe cracking, or rutting. In contrast, capacity expansion decisions are normally made at the planning level in regard to the operational conditions, such as levels of service, travel speeds, or delays. The recently adopted asset management approach calls for integrated decision-making that balances both types of decisions. In this context, this paper introduces a nested Markov decision process (NMDP) framework that can be used to obtain the optimal policy for joint pavement improvement and capacity expansion decisions. The applicability of the proposed NMDP framework is demonstrated through a numerical example showing how a special capacity expansion decision, road widening, can be integrated with conventional pavement improvement decisions for upgrading roadway facilities.