What makes this project so unique?
This bridge will be assembled and opened to traffic in less than two weeks. It would usually take four to five months to construct this bridge with conventional methods.

How will it be constructed so fast?
All structural components of this bridge are made of precast concrete enabling the bridge to be assembled very quickly. Most bridges constructed in NH utilize cast-in-place concrete foundations. Cast-in-place concrete requires time to build formwork, tie reinforcement and time for concrete to cure in each piece of the foundation, increasing the time it takes to construct the bridge. The components used on this project are ready to use when they get to the bridge site.

Why hasn't this technology been used in bridges before?
There are a couple of reasons:

1. Cast-in-place concrete substructures have proven to be very versatile. They are easy to design and construct and are very durable when constructed properly. They have served the transportation infrastructure very well.
2. This new, totally precast concrete, technology introduces additional joints into the structure. Since joints can be a weak link in a structure, Engineers would typically prefer to minimize the number of joints in a bridge in order to reduce maintenance and make it last longer. Each foundation of this bridge would be built using five separate concrete pours if constructed with cast-in-place concrete. In contrast, each precast foundation used on this project is made of eleven pieces. Each of these individual pieces must be connected together to create a structure that acts in unison to support the bridge. A relatively new type of connector is being used to accomplish this. The performance of these joints/connections will be closely monitored.
3. Cost. Any time you accelerate construction it costs more.

Is this new technology safe?
The connector being used to connect the precast pieces has been used in Japan for a number of years with great success. It has also been used in this country by the building industry. The FAA is using this connector in the air traffic control towers they are constructing. The new tower under construction at the Manchester Airport is made of precast concrete components and uses this type of connection.

How does the traveling public benefit from this new technology?
This new technology will reduce construction related traffic delays on high volume roads by minimizing the duration of construction projects. This will improve work zone safety for both the traveling public and construction workers.

How do the costs compare to conventional methods?
A new technology is usually more expensive. It is a little early to tell, but we estimate this might increase total project costs by approximately 25%. We think the costs will be reduced as it becomes more commonplace in the industry.
Also, this cost increase does not reflect user cost savings. There are definite savings when thousands of commuters don't have to sit 30 minutes a day in traffic back-ups caused by construction projects that occur over many months. In addition, construction work zones are very prone to accidents and there will be a cost savings due to accidents that will be avoided by reducing the duration of bridge construction projects. These are savings that are difficult to quantify but based on rough estimates, the engineering community believes that this technology, used in appropriate applications, will result in significant net savings.