North Carolina Bridge Information
North Carolina Bridge Information
NCDOT is responsible for maintaining the safety of more than 13,500 bridges and an additional 4,500 large pipes and culverts along the state’s highways. These bridges are critical links in North Carolina’s highway system, one of the largest in the nation. As infrastructure needs have grown, funding has not kept pace. To help address this funding gap and make the most efficient use of limited dollars, our comprehensive bridge program’s focus is to ensure that we are making the best use of available funds toward the specific needs of each bridge, improving safety and access across the state, which bolsters economic growth.
By the Numbers
- 18,000 – total number of structures we maintain, third most in the nation:
- 13,500 – bridges maintained by NCDOT
- 4,500 – culverts and pipes in addition to the bridges
- About 5,100 – bridges considered structurally deficient or functionally obsolete
- $16 billion – cost of replacing all bridges considered to be substandard (either structurally deficient or functionally obsolete)
- $11 billion – the cost to improve all current substandard bridges through either replacement, rehabilitation or preservation, so they are no longer considered substandard
Funding Breakdown for Fiscal Year 2014
|State funds for bridge improvement:
|Federal Funding to our bridge program:
Bridge Health Index
NCDOT is committed to measuring and improving our overall performance. One of our goals is to make our infrastructure last longer by setting a target for at least 65 percent of our bridges rated to be in good condition or better. “Good” means that the deck, substructure and superstructure each score a six or greater on a nine-point scale. To get there, we use a data-driven strategy to improve the overall condition of all bridges in our state by focusing taxpayer dollars where they're needed most.
Improving North Carolina’s Bridges
For years, the number of bridges the department improved or replaced annually wasn’t keeping up with the number of bridges that were becoming deficient, so we reevaluated our bridge program to find ways to make it work better. As a result, we modified the program into a comprehensive strategy that focuses on timely maintenance, rehabilitation and replacement. We also make preserving bridges a priority, which extends their usable lives and prevents costly repairs in the future.
This new approach makes the best use of limited funding and enables us to upgrade North Carolina’s bridges faster.
State-Funded Bridge Program
In 2011, we worked with the North Carolina General Assembly on an initiative to invest more state funding into our bridges in order to make strides in improving their condition. The result is the State-Funded Bridge Improvement Program. As part of this program, NCDOT is investing about $800 million over four years to not only replace, but also strategically preserve or rehabilitate existing bridges to extend their lifespan at a significant costs savings, stretching taxpayer dollars further while improving more bridges faster. This is the largest bridge program in the state’s history, and is part of NCDOT’s overarching Bridge Program, which uses both federal and state funds.
The N.C. General Assembly approved NCDOT to invest about $450 million for fiscal year 2012-2013. This investment resulted in:
- Improved more than 790 bridges across the state
- 270 fewer structurally deficient bridges
- Improved Bridge Health Index of 570 bridges that were previously rated as “poor”
- 312 fewer bridges with weight restrictions
Based on this success, the N.C. General Assembly approved an additional $330 million in the 2014-2015 budget to continue the program over the next two years.
Before planning a complete bridge replacement, NCDOT instead determines if parts of the bridge can be repaired or replaced. We use this information to evaluate whether it is more cost-effective to replace the bridge or if less expensive improvements will extend its useful life. By doing the right work, on the right bridge, at the right time, we can stretch our dollars further.
- Resurfacing decks
- Painting structural steel
- Cleaning bearings/painting bearings
- Repairing/replacing expansion joints
- Replacing decks or entire superstructure
- Increasing the vertical clearance of low bridges (jacking) to stop them by being hit bridges
- Rehabilitate superstructure
- Replacing an existing bridge with another bridge, or sometimes with a culvert or pipe.
The department has a number of methods to replace a bridge, and is careful to select the best method for each project, which can help speed up overall construction and delivery time.
Low-Impact Bridge Program
NCDOT worked with an interagency team of its state and federal agency partners to create a streamlined bridge replacement process called the Low-Impact Bridge Replacement Program. Projects in this program are typically small in size and are replaced within the same environmental footprint. The implementation of this program in 2010 has resulted in decreased overall project delivery time from 5 years to about 2 years, from programming to completion.
- Conventional Design, Bid, Build
This method is the traditional way to design and construct a project. The project is planned and designed first. The construction phase of the project is then advertised and awarded to a private contractor.
- Design-Build/Express Design-Build
- o Design-Build allows the Department to contract a team that consists of both designers and a contractor to simultaneously design and construct a project. Projects can be let sooner and completed faster using this approach. This process also typically involves a two-stage evaluation process which consists of shortlisting contractors and evaluating proposed designs.
- o Express design-build does not require a technical proposal, and is more efficient than traditional design-build for less complex projects that do not require additional land acquisition. Contracts typically include a cluster of bridges to be replaced. Each bridge is designed, constructed and completed in about a year.
- New design guidelines for lower-volume roads
For roads that have little traffic, bridge engineers developed guidelines that allow for safety improvements while also right sizing bridges on these type roads.
- Standard bridge plans for small bridge replacements
To save on design costs and develop plans quicker, standard plans were established for certain types of bridges with spans of 25 feet to 100 feet in length, and 27 feet to 39 feet wide.
List of Bridges and Current Status
Snapshot of # of Planned Projects
The table below depicts a snapshot of the total number of NCDOT bridge projects expected to be awarded in each Division through the end of 2014.
|Forecasted Bridge Projects to be Awarded Between July 2011 & December 2014
|TIP Bridge Rehabilitation (Federally Funded)
|TIP Bridge Replacement (Federally Funded)
|TIP Bridge Preservation (Federally Funded)
|BD Low Impact Replacement (Federally Funded)
|BP Bridge Preservation (Federally Funded)
|BK Bridge Replacement (Federally Funded)
|ST Bridge Preservation (State Funded)
|ST Bridge Rehabilitation (State Funded)
|ST Bridge Replacement (State Funded)
|Maintenance - Bridge Maintenance Funds (State Funded)
|Grand Total (subject to change as structures are added or removed from program):
- TIP Bridge Rehabilitation
- TIP Bridge Replacement
- TIP Bridge Preservation
- BD Low Impact Replacement
- BP Bridge Preservation
- BK Bridge Replacement
- ST Bridge Preservation
- ST Bridge Rehabilitation
- ST Bridge Replacement
- Maintenance - Other State Funds (ST)
Bridge Project Map/Project Lookup
- NCDOT inspects each bridge in North Carolina at least every two years in accordance with the National Bridge Inspection Standards.
- Any identified structural problem is addressed by contract repairs or by NCDOT bridge maintenance crews, which are located across the state.
- If a bridge is considered unsafe, we immediately make repairs or close the bridge to traffic.
- NCDOT inspects about 9,000 structures each year with the help of private engineering firms.
How inspections work
All bridges go through a natural deterioration or aging process, although each bridge is unique in the way it ages. Regular inspections help the department identify whether a bridge needs maintenance and repair, and then schedule them accordingly. If we find a safety concern, we make repairs immediately or we will close the bridge until the repairs can be made. If necessary, we will post weight restrictions on a bridge. We will not keep a bridge open if it is determined to be unsafe.
Survey teams assess the condition of all elements on each bridge during an inspection, including:
- Expansion joints
A team of divers trained in underwater bridge inspection will examine any parts of the bridge that are underwater.
The condition of the major components is then recorded into a statewide bridge database, along with the type and extent of repairs needed, if any. A thorough structural analysis is performed and safe load carrying capacities are determined. If necessary, weight restrictions are placed on the bridge.
The sufficiency rating is calculated based on a formula defined by the Federal Highway Administration that places 55 percent value on the structural condition of the bridge, 30 percent on its serviceability and 15 percent on how essential it is to the public.
NCDOT inspects all state-owned structures. Municipalities are responsible for inspecting their own structures.
Commonly used bridge terms
Structurally Deficient – This means that while the bridge remains safe, it requires repairs and was built to design standards no longer used for bridges. A bridge is considered structurally deficient if it is in relatively poor condition, or has insufficient load-carrying capacity. The insufficient load capacity could be due to age, the original design or to wear and tear.
Functionally Obsolete - This means the bridge is safe, but needs to be replaced to meet current and future traffic demands. A bridge is considered functionally obsolete if it is narrow, has inadequate under-clearances, has insufficient load-carrying capacity, is poorly aligned with the roadway, and can no longer adequately service today’s traffic.
Sufficiency Rating - A bridge sufficiency rating includes a multitude of factors: inspection results of the structural condition of the bridge, traffic volumes, number of lanes, road widths, clearances, and importance for national security and public use, to name just a few. It is calculated per a formula defined by the Federal Highway Administration. The point calculation is based on a 0-100 scale and it compares the existing bridge to a new bridge designed to current engineering standards.
The bridge’s sufficiency rating provides an overall measure of the bridge’s condition and is used to determine eligibility for federal funds.
Definitions of bridge terms (Courtesy of AASHTO)
Bridge Guidelines, Stats, & Studies
For bridge load and permit questions contact the Oversize / Overweight Permits Unit:
For more information and general questions regarding bridges:
- Phone: 1-877-DOT-4YOU (1-877-368-4968)
- Email: Contact Us
For information regarding administration of bridge policies and procedures contact Bridge Management: