Roads

Introduction

Roads, usually referred to as collectors, arterials and freeways in the U.S., are roadways where through movements are prioritized over access movements. Roads are safer, faster, and have higher capacity per unit of area when access is properly managed. The main function of a road is to enable safe and efficient mobility for all road users, including those outside of a car.

General Design Considerations

Access control.

Layout considerations for rural and suburban.

Minimizing complexity/conflict points

Minimizing maintenance costs, asphalt, land use.

Externalities

Matching perceived risk to actual risk.

Urban Roads

Urban Core, Urban and Rural Town contexts

Example of an urban road (Amagerbrogade, Amager, Copenhagen)

Example of higher capacity urban road (New York Avenue, Washington DC)

Urban roadways are one of the most difficult challenges in transportation engineering, and the best solution for a given project will vary significantly depending on the local context. Higher density environments increase conflict points and externalities, creating uniquely difficult safety and economic challenges. Many urban roadways have high enough impacts on the success of the surrounding neighborhood that converting them to streets actually improves overall prosperity within the city. The rest of this section covers best practices for when the local comprehensive transportation plan has determined that providing a high performance facility for motor vehicles is worth the costs.

Suburban Roads

Suburban context

Rural Roads

Rural context

Rural road with full access control and rumble strips.