Maintenance activity on two-lane highways often requires the closure of one travel lane. Vehicles in both directions of travel are served via the one remaining lane. Under such conditions, alternating right of way into the highway’s work zone is provided to each direction of travel. This so-called “one-way traffic control” typically creates significant motorist delays. This paper describes a proposed technique for estimating vehicle delays and queue lengths on two-lane highways operating under one-way traffic control. Using parameter estimates derived through empirical data, the procedure estimates the average amount of time right of way is extended to each direction of travel during a given time period of operation. Average motorist delays and queue lengths occurring over the given time period are then computed using deterministic queueing theory. The proposed technique can aid highway agencies in determining the appropriate physical lengths and/or hours of operation for two-lane highway work-zone segments.