Automated Traffic Signal Performance Measures: A Program Approach

Lake County, situated in the northeastern most corner of Illinois, USA, has a current population of more than 700,000-a population growth of 36 percent since 1990. The Illinois Department of Transportation (IDOT) found that there was an increase of approximately 875,000 daily vehicle miles (1.4 million kilometers [km]) of travel in Lake County (six percent growth) from 2010 to 2017, and this growth is expected to continue. Traffic congestion impacts the quality of citizens' daily lives-time spent frustrated in traffic backups means less time with one's family. The Lake County Division of Transportation (LCDOT) has been using Synchro traffic analysis software to evaluate intersection operations and performance. Table 1 summarizes the levels-of-service (LOS) for each of the county-involved, signalized intersections and roundabouts currently modeled in the Synchro model. LCDOT recognizes that effectively addressing congestion issues is not simply adding new lanes to our highway system, but making the roads work better.