Discussion and Review of Highway 6 Reconstruction Project and the Intersections of Croell Avenue and Kimberlite Street

Tra ic Growth & Future Development Tra&ic counts were collected on August 5, 2025, during weekday AM and PM peak hours. Growth projections extended to 2045, incorporating background tra&ic and tra&ic generated by nearby planned developments north of US 6, including: • 44 single-family homes • 154 duplex/townhome units • 14 acres of mixed-use commercial development • 10,000 sq. ft. University of Iowa clinic A 4.3% annual tra ic growth rate was applied to US 6 based on Iowa DOT historical data—higher than typical growth rates, but representative of recent local trends. Operational analyses were conducted using Synchro 12 and HCS software following Highway Capacity Manual (HCM 7th Edition) methodologies. Key Terminology • Level of Service (LOS): A measure of intersection e&iciency based on vehicle delay. o A–D = Acceptable, E–F = Poor/Overcapacity • 95th Percentile Queue: The queue length expected to occur during the busiest tra&ic periods. • TWLTL (Two-Way Left-Turn Lane): A shared center lane that allows vehicles traveling in either direction to make left turns. Existing Conditions (2025) • Croell Avenue: Operates acceptably overall (LOS D or better), except for the southbound left-turn, which experiences significant delay (LOS F) during the PM peak. o Crash data (2019–2024): 12 crashes, primarily angle-type collisions involving southbound left-turn movements.