Innovative Aurora Traffic Design Commands Attention

In recent years, the City of Aurora, Illinois, embarked on a cutting-edge program to interconnect and modernize its antiquated traffic signal systems. Long-time partner HR Green as a traffic engineering consultant for the City was selected to assist in achieving four critical goals for the City of Aurora, including:

1. Moving vehicles more efficiently throughout the City.
2. Finding opportunities to reduce the City’s energy consumption.
3. Equipping the City’s signal system with emergency vehicle pre-emption.
4. Enhancing the Downtown corridors.

HR Green engineers, partnering with Aurora, utilized the City’s existing fiber-optic backbone to develop a Centralized Traffic Management System (CTMS) encompassing ten routes spanning 17+ miles. The CTMS uses a combination of pavement loops and video cameras to monitor and effectively move traffic at more than 70 intersections throughout the City. Archaic traffic signals at those intersections were upgraded with modern signals using programmable controllers and energy-efficient LED light sources. Vehicle detection information, including live footage from the video cameras, is transmitted to a command center at City Hall by a combination of fiber-optic cable and wireless radio antennas. In the command center, City traffic engineers can control the traffic signals at any intersection to optimize traffic flow in any direction. By installing uninterruptible power battery backup for all signals, HR Green’s engineers ensured continuous service to pedestrian and motorized travelers throughout the system.

HR Green was recognized with a 2012 ACEC-IL Engineering Excellence Merit Award. The HR Green Team successfully met the City’s four goals, and delivered the following benefits to the City’s staff, residents, and traveling public (i.e., the consumer):

1. Enhanced drive time with less wasted fuel
2. Upgraded air quality via reduced fuel consumption
3. Improved traffic flow for emergency vehicles
4. Reduced electric bills
5. Added archival footage for accident investigations

Downtown areas complicate a traffic modernization project because convenient bury space for fiber-optic cable is virtually nonexistent. Concrete sidewalks span the entire distance from the roadway curb to the building front. Moreover, those sidewalks frequently hide vaults and storage areas that extend from basements under the right-of-way. Removing a slab can open a whole world of unforeseen problems.

These problems were avoided by using wireless radio transceivers with multidirectional antennas. HR Green worked with product suppliers and manufacturers to determine the appropriate locations and equipment needed for multidirectional antennas, cameras (pan-tilt-zoom and vehicle detection), fiber-optic splicing, Ethernet switches, and terminal servers.

Using innovative, wireless technology, HR Green eliminated the cost and pedestrian inconvenience that sidewalk demolition would incur amidst the downtown area. Conversely, in suburban areas, the grass boulevards made fiber optic installation more economical.

The City of Aurora’s project satisfaction is evidenced by its eagerness to expand the system and continue its partnership with HR Green to realize this expansion. At the time of this writing, three more corridor interconnect projects are under construction. Ultimately, the City anticipates tying all 100+ signalized intersections within the CTMS.