The "First State" has a solid history of measured growth to maintain safety along its busiest roads. That's thanks to the Delaware Department of Transportation (DelDOT) Corridor Capacity Preservation Program (CCPP). What began as a pilot program in 2001 is a now a guide to innovative corridor capacity preservation.

Delaware's growth was a driving force behind the creation of the CCPP. In the 10 years from 1990 to 2000, the state's population increased by over 114,000 to almost 784,000. By 2020, projections show the population will reach around 1 million Delaware residents. Add to those numbers the hundreds of thousands who come to do business, visit historic attractions or head to the popular downstate beaches. Finally, as the second smallest state with only three counties, the reasons for growing congestion is understandable.

Preserve Roads and Improve Safety

In accordance with Delaware Code, Title 17, Section 145, the program officially started in February 1997. Its focus is specific - to preserve roads, improve safety and focus development toward areas where infrastructure already exists. It helps landowners, developers, businesses, legislators and others understand the goals, objectives and preservation techniques the DelDOT is using to retain capacity on the state's major highways, particularly those that predominantly serve statewide or regional travel.

In the past, if businesses and homes built up along an arterial road to the point that traffic slowed and accidents increased, Delaware built a new road around it. Today, constructing new roads has become a solution of last resort, not only because of the costs to build and maintain roads and bridges and support infrastructure, but also because land and rights-of-way are increasingly difficult, and sometimes impossible, to secure. "More pavement attracts more traffic, all in an ongoing cycle that increases air, water and noise pollution, swallowing up trees and farmland, and eventually drawing even more cars and trucks to the new road," says Tom Felice, P.E., a Transportation Engineer with DelDOT and Project Manager for the program.

"The CCPP looks ahead in planning how to get the most out of our existing roadways. We develop concepts or improvements to certain intersections and once those concepts are deemed acceptable, we hand off them to our design team. From there, that initial design goes to the public for approval through public workshops," he notes. "By law in Delaware, we must have the public's feedback for major projects before we proceed with final design."

Highlighting the Program Goals

The main goals of the Delaware CCPP are around preserving the traffic capacity and maintaining safe travel centers on four key designated corridors, including portions of State Road (SR) 1, U.S. 13, U.S. 113 and SR 48. Access options along the corridors vary by location and are delineated into four types of investment areas:

·      Level 1: Communities - State policies encourage redevelopment and reinvestment. Level 1 designation permits direct access.

·      Level 2: Developing Areas - State policies promote orderly growth. Level 2 designation can permit direct access.

·      Level 3: Secondary Developing Areas - State policies promote orderly development within the limitations of state financial resources. With Level 3 designation, there is no direct access.

·      Level 4: Rural Areas - State policies encourage the preservation of a rural lifestyle and discourage new development. Level 4 designation also does not permit direct access.

Felice explains that in Levels 3 and 4, those investment areas may get an interchange and service road only. Each level within the program has its own Access Management Plan. Access Management is the process of maintaining roadway safety, capacity and mobility by managing driveway spacing and operations along a road corridor. "Primarily, if a property has reasonable alternative access to a secondary road, no direct access to the corridor will be permitted," he says. Specifically, the program serves 31 miles of SR 1 from Dover south to Nassau; 46 miles of U.S. 13, from Route 10 to the Maryland State line; 33 miles of U.S. 113, from the southern limits of the City of Milford to the Maryland State line; and 2 miles of Route 48 near Wilmington, from Hercules Road to Route 41.

The CCPP encourages interconnections between developments and the implementation of service road networks, which help minimize and consolidate the amount of direct access points (driveways) along the corridors. "In some cases, DelDOT develops grade separated interchanges to help improve traffic circulation and operations between heavily traveled sections of roads," says Felice. Grade separated interchanges are elevated freeway connections which use ramps to accommodate high traffic volumes through a given junction. "These are just a few of the strategies the program uses to maintain the capacity of the corridors," he continues.

For example, the goal for SR 1 is better access from Wilmington to the beach areas. "It was determined that SR 1 would be a limited access highway from Interstate 95 to the beaches, taking away all traffic lights. The section from Wilmington to Dover then would become a toll road. We want to limit access and will do so through grade separated interchanges," Felice notes. "With the Corridor Plan, we can maximize the existing road by reducing the amount of conflict points and preserving the traffic capacity on the arterial."

The largest investment within the four CCPP program areas in the SR 1 Corridor section of the project. According to Felice, one particular section that encompasses many goals of the overall project is the Little Heaven interchange on SR 1. This section includes service road development, minimizing conflict points along the corridor, reducing the amount of signalized intersections on the corridor and safely routing traffic through an interchange.

Environmental Concerns

As with all transportation projects, there is an environmental impact that comes with the CCPP.

"A key environmental issue we work to address is reducing the number of cars sitting idle, which improves the carbon monoxide emissions," Felice notes. "When we developed the interchange concepts, we tried to avoid any conflict with wetland areas. One of the rare environmental instances we encountered had to do with bog turtles near the beach area. If we spot a bog turtle nest, we will change the alignment of the concept for that area."

Historic sites also are given special consideration. Along the SR 1 Corridor north of Frederica in Kent Count is the Barratt's Chapel graveyard. Built in 1780, DelDOT made sure there were no alignment issues with that historic site. "There's actually a curve in the roadway's alignment in order to avoid the area," Felice says. 

A summary of the DelDOT Corridor Capacity Preservation Program may be found at  

deldot.gov/information. The complete Workbook for Innovative Corridor Capacity Preservation Pilot Program is also featured on the U.S. Department of Environmental Protection's (EPA) website.