The purpose of this study is to evaluate potential travel time impacts of the implementation of exclusive heavy-vehicle lanes on the Interstate Highway 35 (IH 35) corridor, in the Austin metropolitan area. The analysis considers heavy vehicles (trucks) and non-heavy vehicles (cars) as separate system elements and as an integrated system. The study modeled traffic operations on IH 35, during the AM and PM peak hours, under two traffic scenarios, Existing and Inside Truck-Only Lanes using the software VISSIM 5.4. The limits of the study are FM 1431 in Round Rock, on the north, and SH 45 near Buda, on the south. The Existing scenario modeled traffic operations under current IH 35 geometric conditions and traffic control rules, in which trucks are prohibited from the inside lane and cars are allowed in all lanes. The Inside Truck-Only Lanes scenario modeled traffic operations under the assumption that trucks are restricted to the inside lane only and cars are prohibited from the inside lane. Travel times across the study area corridor were measured in the models to compare the performance of the Inside Truck-Only Lanes scenario relative to the Existing scenario. / text