Discover published sets by community

Determines the roadway's structural capacity, drainage, and vehicle accommodation. Standards: Lane width, shoulder width, pavement structure

Defines the edge of the roadway, aids in drainage, and provides a physical barrier for sidewalks. Standards: Profile, material, gutter flow capacity

Affects the operational efficiency and maneuverability of vehicles. Standards: Typically 3.0 to 3.75 meters; varies by vehicle type and road use

Guides and controls traffic flow and provides critical information to drivers. Standards: Colors, widths, and patterns specified by the MUTCD or local guidelines

Provides space for stopped vehicles and emergency use. Standards: Based on functional classification of the highway, traffic volume

Ensures visibility and safety over hills and dips, optimizing drainage and snow removal. Standards: K-value for sag and crest curves, stopping sight distance

Area adjacent to the roadway clear of obstructions for safety. Standards: Depends on speed, volume, and road type; AASHTO guidelines

Conveys regulations, warnings, and guidance information to road users. Standards: Size, height, reflectivity, and placement governed by MUTCD

Minimum distance required for a driver to detect an unexpected hazard and execute a safe maneuver. Standards: Longer than stopping sight distance, factors in driver perception-reaction time

Facilitates the safe and efficient movement of traffic between different roadways. Standards: Turning radii, sight distance, lane widths, signalization

Prevents vehicles from leaving the roadway and entering dangerous areas. Standards: Types include guardrails and concrete barriers, designed to NCHRP Report 350

Controls the flow of traffic at intersections to minimize conflicts and delays. Standards: Locational needs and timing intervals, MUTCD regulations

Used to reduce vehicle speeds and improve safety for pedestrians and cyclists. Standards: Speed bumps, chicanes, curb extensions, guidelines vary by jurisdiction

Affects tire grip, ride quality, and water drainage. Standards: Texture, skid resistance, and smoothness; adherence to material specifications

Mitigates transportation-related noise impacts on adjacent sensitive land uses. Standards: Height and material density to achieve desired noise reduction, aesthetic considerations

Minimum length of roadway ahead visible to the driver to allow safe maneuvering. Standards: Stopping sight distance, decision sight distance, passing sight distance

Smooth change in curvature and super-elevation to aid in driver comfort and vehicle stability. Standards: Transition lengths based on AASHTO criteria, spiral curves

Determines the speed vehicles can travel safely under ideal conditions. Standards: Influences all geometric elements, set by regulatory bodies

Separates opposing traffic directions to reduce head-on collisions. Standards: Width depends on traffic volume and vehicle type, barrier specifications

Aims to slow traffic and reduce severe accidents at intersections. Standards: Inscribed circle diameter, deflection angles, approach widths

Accommodates cyclists with safe and efficient travelways separate from vehicular traffic. Standards: AASHTO Guide for the Development of Bicycle Facilities, width, and surface standards

Provides spaces for vehicle storage that meet user needs and safety. Standards: Stall dimensions, circulation patterns, aisle widths, ADA compliance

Elevation change over a specified distance, influencing the road's drainage and vehicle operation. Standards: Maximum and minimum grades determined by terrain and design speed

The distance needed for a vehicle to come to a complete stop after an obstacle is visible. Standards: Based on reaction time, deceleration rate, and initial speed

Facilitates foot traffic separate from vehicular ways to ensure pedestrian safety. Standards: Width, grade, surface material, ADA accessibility

Provides a safe pathway for vehicles to follow, without unreasonable sharp curves, to maintain speed and comfort. Standards: AASHTO guidelines, minimum radius based on design speed and lateral friction

Improves visibility at night and during poor weather, enhancing safety and security. Standards: Illuminance levels, pole spacing, light color and distribution

Outward tilt of the road curve to help vehicles counteract centrifugal forces at high speeds. Standards: Rates vary with design speed and radius, AASHTO guidelines

Distance required to safely pass another vehicle on two-lane roads without causing head-on collisions. Standards: Based on speeds of passing and opposing vehicles, and driver reaction time