There are four basic types of physical improvement projects, some of which must comply with standards and others that do not have to comply. These types of improvement projects are discussed in the following paragraphs.
As its name implies, this action involves the construction of a new highway facility. This might take the form of a bypass constructed to carry through-traffic around an existing town or it might be a new two-lane access route linking an existing arterial highway with a State park.
This typically involves a major change to an existing highway within the same general right-of-way corridor. In many parts of the country, roads that were originally constructed in the early 20th century as two-lane farm-to-market roads have been reconstructed over the past few decades into multilane divided arterials to better accommodate the travel demands generated by suburban development. Reconstruction also may involve making substantial modifications to an older highways horizontal and vertical alignment in order to eliminate safety and accident problems.
3R projects focus primarily on the preservation and extension of the service life of existing facilities and on safety enhancements. Under the classification of 3R projects, the types of improvements to existing federal-aid highways include: resurfacing, pavement structural and joint repair, minor lane and shoulder widening, minor alterations to vertical grades and horizontal curves, bridge repair, and removal or protection of roadside obstacles. Transportation Research Board Special Report 214, Designing Safer Roads, Practices for Resurfacing, Restoration, and Rehabilitation (1987), documents the result of a study on the cost effectiveness of highway geometric design standards for 3R projects. Each State was invited to develop and adopt minimum design criteria for non-freeway 3R projects. The result is that States typically employ design criteria for 3R projects that are lower than those contained in the AASHTO Green Book.
“Typically, maintenance activities consist of those actions necessary to keep an existing highway facility in good condition. CSS is increasingly concerned with monitoring operation of a facility however and making adjustments to the design to make the road responsive to its context.” Maintenance activities include repainting lane and edge lines, removing accumulated debris from drainage inlets, repairing surface drainage features, mowing, and removing snow.
Source: Flexibility in Highway Design pp. 30-33
Published: 1997
