Safe roadway design and types of highway design defects

Highway design engineers work from widely accepted design principles that, when followed, create a road environment that is safe for all road users, including pedestrians, bicyclists, motorcycles, as well as cars and trucks. The goals of safe roadway design include:

  • All users of the roadway will have consistent information about the road ahead, provided in sufficient time to respond to it.
  • Visibility will be adequate, and visual barriers will be eliminated.
  • Warning will be given for any changes in the road condition or for substandard features in the roadway.
  • Warning and guidance will be given for unusual changes in the road.
  • All roadway users will be alerted to conflict points such as intersections, and control users’ progress through these.
Intersecting bridges

The Federal Highway Administration notes that in highway design, every project is unique, and no single set of solutions works for all roadways. The area’s unique setting and character, its geographic features, the community’s priorities, and the needs of users of the roadway must be considered with each highway project. On every project, designers must develop solutions that integrate the design into the natural and human environments in a way that makes the road safe for all roadway users.

State and local governments usually have strong and necessary safety standards, and a set of good design principles that support their standards. Roadway design defects tend to occur when a county or state road department fails to follow its own standards.

A wide range of roadway design defects can cause serious injury and death. A few examples include

  • Plantings and other vegetation that blocks users’ view of the road
  • Trees and other immovable objects too close to the road
  • Poor sightlines
  • Insufficient drainage that results in excessive water on the road
  • Nonfunctioning or missing traffic signals
  • Inadequate shoulders
  • Inadequate guard rails or other barriers
  • Poorly designed access ramps
  • Inadequate or missing signage
  • Lack of a clear recovery zone

California law requires all its cities, counties, other municipalities, and the state itself, to build safe roadways and maintain them in safe condition. When a governmental entity’s failure to design, build and maintain is a substantial factor in causing an injury or death, the injured party may recover damages.

Highway Design Defect Resource
110 Laurel St. • San Diego, CA
619 238-1811