We’ve all been there: sitting in a seemingly endless line of traffic because of bridge construction, which either led to partial lane closures or some out-of-the-way detour. Approximately ¼ of America’s 600,000 bridges are in need of repairs or even total replacement, but, despite the dangers of driving across bridges requiring maintenance, most people still don’t want their commutes disrupted because of construction.
It seems like a lose/lose situation: either repair the bridges and disrupt many people’s commutes for extended periods of time or wait to repair the bridges and hope no accidents happen. That’s a risk not many people in the public infrastructure industry are willing to take.
So what’s the solution?
While we can’t snap our fingers and have America’s bridges be in perfect condition without disrupting anyone’s commute or causing unsafe driving conditions, Accelerated Bridge Construction (ABC) is a close alternative.
ABC is bridge construction that uses innovative planning, design, materials and construction methods in a safe and cost-effective manner to reduce the onsite construction time (and subsequent traffic delays) that occurs when building new bridges or rehabilitating existing bridges.
- Improved Safety– The Federal Highway Administration (FHWA) reports that there are roughly 2,000 fatal crashes in work zones each year, and 44% of bridge construction worker injuries involving a vehicle traveling through a work zone. 2/3 of these injuries are fatal. With ABC, the time bridge construction workers spend in an active work zone is reduced, which means they will be out of harm’s way faster than with traditional bridge construction timelines.
- Public Opinion– Americans are busy. They have places to go and people to see, which is why a lengthy detour or lane closure is not on anyone’s wish list. With ABC, bridge construction takes up as little time as possible, which means shorter periods of frustration for the public.
- Budgetary Concerns- Lengthy constructions don’t just take up time- they also cost money. The longer the construction or repair period, the more money is spent. With ABC, there is less time spent on each bridge, which means less money spent.
In 2009, the FHWA, in partnership with the American Association of State and Highway Transportation Officials (AASHTO), launched the Every Day Counts (EDC) initiative for faster delivery of highway projects and an improved way to handle limited budgets.
Three ABC technologies are promoted under the EDC initiative:
- Geosynthetic Reinforced Soil-Integrated Bridge System (GRS-IBS)– A construction method which combines closely spaced geosynthetic reinforcement and granular soils into a new composite material. This is used to construct abutments and approach embankments less likely to result in a ‘bridge bump’. According to the FHWA, the GRS-IBS method is 25-60% more cost-effective than conventional construction methods.
- Prefabricated Bridge Elements and Systems (PBES)– PBES are structural components of a bridge that are built offsite, which reduces onsite construction time and mobility impact that would typically be involved if these conventional methods were used.
- Slide-In Bridge Construction (SIBC)– SIBC is a technique for quickly replacing an existing bridge. The new bridge is built on temporary supports parallel to the existing bridge. Once all construction is finished, the existing bridge is demolished, then the new bridge is simply slid into place, tied in to the approaches and paved within 48 to 72 hours.
According to the FHWA, accelerated bridge construction innovations have already been deployed nationwide, with several states currently developing new policies for utilizing ABC methods in future projects.
ABC technologies have changed the way bridges are built and repaired. With so many of America’s bridges in need of repairs, implementation of accelerated bridge construction throughout the country improves safety, mobility and costs, all at a fraction of the time.