The intersection of Burlington Road and Illinois Route 47 in Campton Hills, Illinois was a four‐way stop between two two‐lane highways. All‐way stop control eliminated a rash of severe crashes but was insufficient to handle growing traffic volumes. Initially, the Kane County Division of Transportation (KDOT) saw a traffic signal concept as the answer – but storage and taper requirements used pavement inefficiently and reintroduced safety concerns. When expanding pavement, drainage and right‐of‐way requirements threatened to price the improvement out of budget, KDOT directed their consultant, Burns & McDonnell, to find another way.

KDOT and Burns & McDonnell brainstormed the idea of a roundabout. The case for it was so compelling that the Illinois Department of Transportation (IDOT) quickly approved the change to a roundabout – a first for an arterial highway in northeastern Illinois. The new roundabout required half the pavement of a signalized intersection and cost $1 million less than the final estimate for the traffic signal design. STV’s proactive construction management and Martam’s skilled construction crews kept costs within 2% of the bid price. The expandable design improves capacity and traffic flow, accommodates large trucks and will help encourage more roundabouts in Illinois.