Us 23 Corridor Location Study Preliminary Travel Impact Analysis PDF Download

Howard R. Green Company was retained to complete a corridor study for the US 30/67 Corridor within the City of Clinton from the west intersection of US 30 and US 67 to the intersection of Camanche Avenue and 4th Street. The initial phase of the project was constructed. The second phase, which extends from 14th Street to 4th Street, is currently being designed. This phase includes completion of a travel demand model to forecast future traffic volumes for the corridor and a traffic operations analysis of select alternatives. Traffic forecasts for 2030 were developed using a computer model and validation procedures consistent with recognized transportation planning guidelines. A base year model was created using roadway attribute data from the Iowa Department of Transportation, and socioeconomic data (1990 and 2000 Census data) from the East Central Intergovernmental Association (ECIA). The model network was altered to represent Year 2030 conditions with the addition of programmed and committed projects. Socioeconomic data was estimated by ECIA using historical growth information. Considering future development plans, the City of Clinton Planning Department assigned the future employment and household projections to each travel analysis zone. Year 2030 PM peak turning movement volumes were developed for the preferred design alternative which consists of a one-way couplet utilizing Camanche Avenue for westbound traffic and Liberty Avenue for eastbound traffic from 14th Street to 4th Street. The volumes were entered into a simulation model in order to complete an operations analysis to determine appropriate signal locations and level of service of roadways and intersections for the study area. The approach to the traffic operation analysis is derived from the established methodologies documented in the Highway Capacity Manual. The one-way pair alternative was analyzed assuming three lanes in each direction and a posted speed of 35 miles per hour on each roadway. For this design, signals should be placed at the intersections of Camanche Avenue and 14th Street, Camanche Avenue and 5th Street, Liberty Avenue and 5th Street, and Camanche Avenue and 4th Street at a minimum. With this configuration, signalized intersections will operate at level of service A and B, and thru-stop intersections will operate at level of service A. Camanche Avenue will operate will operate at level of service A, and Liberty Avenue will operate at the level of service A/B boundary. Additional signals may be placed at select locations experiencing high delay on the minor street. These locations include the intersections of Camanche Avenue with 23rd Place and 15th Avenue as well as the intersections of Liberty Avenue with 23rd Place and 15th Avenue. This placement will cause slight reductions of the overall level of service of the corridor, but should still be considered during reconstruction of the corridor.