PHOENIX —The Arizona Department of Transportation will begin work October 1 to replace the State Route 90 bridge over the San Pedro River east of Sierra Vista in Cochise County.
Motorists traveling in the area will see restrictions and temporary traffic signals in place beginning Thursday, September 27 to allow crews to prepare the existing bridge for replacement.
The $7 million project to replace the 57-year-old bridge is scheduled to be completed in 18 months, with a six-month construction shutdown from April 1, 2013 until October 1, 2013 to avoid disturbing the nesting season of migratory birds in the San Pedro Riparian National Conservation Area.
The new bridge, located near mile post 329 and one mile west of High Knoll Road, will feature wider travel lanes, emergency shoulders, new highway approaches and will be six feet higher than the existing bridge.
During each of the six-month construction periods from October through March, motorists on SR 90 will share a single lane controlled by temporary traffic signals.
The temporary signals will regulate traffic around the clock during construction. Delays of six to eight minutes are anticipated with the potential for waiting times as long as 15 minutes during peak travel times.
Some overnight closures of SR 90 will be necessary during the course of construction to safeguard motorists during certain work, requiring detours on State Route 92 and State Route 80. ADOT will provide advance notice of when those overnight closures will be in effect.
During the first six-month phase of construction, crews will replace the eastbound portion of the bridge, with traffic sharing a single lane on the westbound portion of the existing bridge.
Workers will be on site from 6 a.m. until 5 p.m. weekdays.
Crews will demolish the southern half of the existing bridge and construct a new bridge that will be six feet higher above the San Pedro River to meet 100-year-flood plain requirements. The work will require removal and trimming of a limited number of trees in the work area to allow for crews to construct the new bridge. New trees will be replanted in the area to replace the trees that need to be removed.
Construction of the south side of the new bridge – a 17-foot-wide section with a 13-foot travel lane – is scheduled for completion before April 1, 2013, when construction will take a six-month break for the nesting season for the protected Southwestern Willow Flycatcher and other migratory birds.
During the six-month construction hiatus, traffic will use one lane in each direction – eastbound traffic on the newly constructed bridge and westbound on the old bridge – and the traffic signal will not be in use.
On October 1, 2013, work will resume with demolition of the north side of the old bridge and reconstruction of the rest of the new 44-foot-wide bridge. The signal will once again control traffic sharing a single lane on the completed portion of the new bridge.
During construction, pedestrians will not be permitted to cross the bridge for safety reasons and bicyclists are encouraged to avoid using the bridge. Also, the hiking trail that originates at the nearby San Pedro House and passes beneath the SR 90 bridge will be closed during construction. Other trails in the area will not be affected.
When the project is complete in spring 2014, the new bridge will feature two 12-foot travel lanes with 10-foot shoulders for emergency situations and for use by bicyclists.
ADOT encourages motorists to drive safely in the work area and be aware that they will be unable to see oncoming traffic while waiting at the temporary traffic signal.
ADOT works to inform the public about planned highway restrictions, but there is a possibility that unscheduled closures or restrictions may occur. Weather can also affect a project schedule.
For more information about this project, please visit www.azdot.gov/sanpedrobridgeor contact Safford District Senior Community Relations Officer C.T. Revere at 520.705.3574. Local media should contact the ADOT Public Information Office at firstname.lastname@example.org or 1.800.949.8057. Visit www.facebook.com/azdot or www.azdot.gov for more information about ADOT. For more information about ADOT projects and programs across Arizona see the agency's latest blog posts.