Highway Design and Geometric Elements

<p>To improve vehicle handling and safety (C)</p> Signup and view all the answers

<p>Design speed (A)</p> Signup and view all the answers

<p>Sidewalks (C)</p> Signup and view all the answers

<p>Influences pavement life and riding comfort (B)</p> Signup and view all the answers

<p>Type of road surface (A)</p> Signup and view all the answers

<p>Weather conditions (C)</p> Signup and view all the answers

<p>Cumulative vertical undulations of the pavement (C)</p> Signup and view all the answers

<p>Less than 1500 mm/km (A)</p> Signup and view all the answers

<p>Aesthetic design (D)</p> Signup and view all the answers

<p>Wheels skid without revolving (C)</p> Signup and view all the answers

<p>No glare during the day (B)</p> Signup and view all the answers

<p>To drain rainwater from the road surface (A)</p> Signup and view all the answers

<p>0.68 m (C)</p> Signup and view all the answers

<p>Higher crash rates for large trucks (A)</p> Signup and view all the answers

<p>Absolutely impermeable (A)</p> Signup and view all the answers

<p>Water (C)</p> Signup and view all the answers

<p>Concrete roads (A)</p> Signup and view all the answers

<p>Erosion of the road surface (C)</p> Signup and view all the answers

<p>2.0 m (B)</p> Signup and view all the answers

<p>Before the construction of a new road (A)</p> Signup and view all the answers

<p>2 meters (D)</p> Signup and view all the answers

<p>Edge of pavement (D)</p> Signup and view all the answers

<p>250 ft (A)</p> Signup and view all the answers

<p>Stability for earthworks (C)</p> Signup and view all the answers

<p>When slopes are steeper than 1:2 (D)</p> Signup and view all the answers

<p>Type of vehicle (B)</p> Signup and view all the answers

<p>3.5m (C)</p> Signup and view all the answers

<p>To control drainage (C)</p> Signup and view all the answers

<p>Separating opposing traffic (B)</p> Signup and view all the answers

<p>Barrier kerbs (A)</p> Signup and view all the answers

<p>1.2m to 24m (B)</p> Signup and view all the answers

<p>1.80-2.40m (A)</p> Signup and view all the answers

<p>5 to 8 percent (B)</p> Signup and view all the answers

<p>At sections with high fills (C)</p> Signup and view all the answers

<p>2% to 6% (C)</p> Signup and view all the answers

<p>Low or mountable kerbs (A)</p> Signup and view all the answers

<p>Separating opposing traffic (A)</p> Signup and view all the answers

<p>They are more frequently provided in urban areas. (A)</p> Signup and view all the answers

<p>3.65m (C)</p> Signup and view all the answers

<p>4% to 6% (C)</p> Signup and view all the answers

<p>To prevent vehicles from leaving the roadway (C)</p> Signup and view all the answers

<p>Submerged kerbs (D)</p> Signup and view all the answers

The design of visible highway components, focusing on driver needs and safety.

Visible road features like lanes, shoulders, alignments, and intersections, impacting traffic flow and safety.

The terrain (plain, rolling, mountainous) affects the design elements of a highway or road.

Highway design elements are closely tied to the intended use speed of the road.

User characteristics (vehicles, people) and traffic volume impact road design standards.

The parts of a highway's profile, including travel lanes, shoulders, medians (multi-lane highways), and marginal elements like barriers, kerbs, and gutters.

The resistance between a vehicle's tires and the road surface, important for safe driving and braking.

Fluctuations in the road surface height, affecting driving comfort, safety, and vehicle performance.

A measurement of pavement unevenness, calculated by the cumulative vertical undulations per unit road length.

A measure of the friction between the tire and the road surface.

The material that forms the road surface, such as asphalt, concrete, or earth.

The state of the road surface, including factors like smoothness, damage, and presence of substances like oil or water.

The maximum speed at which vehicles can travel safely on a road section considering factors including friction and curves.

Water is the main enemy of pavement due to its ability to seep into the layers and cause damage.

Camber is a cross-slope provided to drain rainwater, protecting the pavement surface, sub-grade, and promoting quick drying for safety.

The minimum lane width for a single lane road is 3.75m, considering the maximum vehicle width (2.44m) and the desired side clearance (0.68m).

Narrower lane widths, especially below 6.75m, can lead to higher crash rates, particularly for larger trucks, and significantly reduce highway capacity.

Black roads have poor visibility at night because the dark surface absorbs most of the light, making it difficult to see.

If the camber, or cross-slope, is too steep, it can erode the road surface, leading to damage and safety issues.

Concrete roads offer better visibility and less glare compared to other types of roads.

Side clearance is important for safety and operating speed, as it allows for space between vehicles and the road's edge.

The minimum width needed for each lane of a two-lane road is 3.5 meters.

In Iraq, multilane highways use 3.75 meters per lane, while standard roads use 3.6 meters.

Shoulders provide a safe space for vehicles to stop in emergencies or if they have mechanical issues.

Shoulders help support the pavement structure, preventing it from collapsing.

Medians separate opposing traffic lanes on divided highways, preventing head-on collisions.

Medians provide a recovery area for vehicles that might veer out of their lane.

Medians offer stopping areas for vehicles in emergencies.

Medians provide space for vehicles to prepare for left turns or U-turns.

Raised curbs are structures made of concrete or asphalt that define pavement edges and pedestrian walkways, control drainage, enhance aesthetics, and reduce right-of-way.

Barrier curbs are designed to prevent vehicles from exiting the pavement.

Gutters are drainage ditches located beside curbs that collect rainwater and direct it away from the road.

Guardrails are barriers placed along roads to prevent vehicles from leaving the roadway, particularly on curves and high embankments.

Sidewalks are pedestrian walkways typically found in urban areas, providing a safe path for people to walk on.

Low or mountable curbs allow vehicles to easily enter and exit the shoulder, encouraging drivers to stay in through traffic lanes.

Semi-barrier curbs are installed where pedestrian traffic is high, providing a barrier while still allowing for occasional vehicle access to the shoulder.

Submerged curbs are placed between the pavement edge and shoulder in rural areas, providing lateral confinement and stability to the pavement.

Sidewalks need to be at least 1.25 meters wide in residential areas and 1.25 to 2.5 meters wide in commercial areas to allow for comfortable pedestrian movement.

Cycle tracks in urban areas should be at least 2 meters wide. Each additional track adds another meter of width.

Side slopes on embankments and fills provide stability for earthworks and act as a safety feature by creating a space for vehicles to recover if they run off the road.

The three important regions of a roadside for vehicle control are the hinge point, foreslope, and toe of the slope.

The right of way includes all land needed for a highway, including lanes, shoulders, and future expansion.

Factors influencing the right of way width include the highway's category, roadway width, embankment height, cutting depth, side slopes, drainage system size, and the planned use of the area.

A 2-lane road usually requires a right of way width of 150 feet (45 meters).

An 8-lane road usually requires a right of way width of 300 feet (90 meters).