SMALL CITIES/RURAL COMMUNITIES PROJECT OF THE YEAR: TRANSPORTATION
Greenspot Road Bridge over Santa Ana River Managing Agency: City of Highland, California Primary Contractor: KEC Engineering Primary Consultant: Harris & Associates Nominated By: City of Highland, California
he Greenspot Road Bridge over Santa Ana River project is located in the eastern part of the City of Highland, where the prevailing speed is mostly above the posted limits of 55 mph. There is a relative sharp curve on the two-lane Greenspot Road north of the old steel bridge across the Santa Ana River that can only accommodate a reduced speed of 35 mph. The old bridge, with a width of 16’8”, was too narrow to allow safe passage of two opposing standard-sized vehicles crossing the bridge at the same time. It also had a restrictive vertical clearance of 11.5’ and a low weight limit of 10 tons. Across the old bridge, the speed limit was restricted to 15 mph. According to the 2004 Caltrans Bridge Inspection Report, this bridge had an extremely low Sufficiency Rating of 2 out of 100 indicating its severe level of deficiency. This segment of Greenspot Road at and near the old bridge was the frequent site of traffic accidents. This project constructed a much-wider new bridge (98’-wide) eliminating a serious bottom neck across the existing narrow old bridge (16’8”-wide). Traffic on Greenspot Road no longer has to negotiate the relatively sharp turn near the north end of the old bridge, as the 3,487’ of realigned roadway is designed for 65 mph with much smoother curves. The new bridge can accommodate legal loads, and does
not have any vertical clearance restriction. With construction of the project, safe travel over the Santa Ana River is now possible, whether by vehicle, bicycle or foot. The construction process of this project was designed to minimize impact to the travelling public as much as possible. As a result, this project did not cause any traffic impact to the commuters on Greenspot Road during the entire construction period that lasted for 13 months, except for five days when two short portions of Greenspot Road, one on each end of the new bridge, had to be closed to accommodate pavement removal, reconstruction, and connection to the newly realigned roadway segments. This process began by first constructing the new bridge and realigned roadway segments while the existing bridge remained in service with no interruption of traffic on Greenspot Road. After the realigned roadway segments were connected to the existing Greenspot Road, the center two lanes on the www.apwa.net
new concrete bridge structure were immediately opened to traffic, while the outer two lanes remained closed to allow the contractor to complete the exterior bridge barriers. By switching the traffic on the new bridge structure as soon as practical, and closing the old Greenspot Road to perform rehabilitation work on the old steel historic bridge, the public got the benefit of an easier passage through the area three months sooner.