Roadway Design & Engineering Flashcards

In traffic engineering, what does 'LOS' stand for?

Answer: Level of Service

LOS (Level of Service) is a qualitative measure describing traffic flow conditions, ranging from A (free flow) to F (forced/breakdown flow).

What is the minimum recommended sight distance at a railroad grade crossing called?

Answer: Crossing sight distance

Crossing sight distance (also called highway-rail grade crossing sight distance) is the minimum distance a driver must be able to see approaching trains.

A 'crest vertical curve' is used when:

Answer: The road profile forms a hill or high point

A crest vertical curve connects an ascending grade to a descending grade, forming a summit or high point in the road profile.

Which of the following best describes 'context-sensitive design' in roadway engineering?

Answer: Balancing roadway function with community values and environmental context

Context-sensitive design balances transportation function with the surrounding community, environmental, and aesthetic context to develop appropriate roadway solutions.

What is the purpose of a 'taper' in a lane drop or merge area?

Answer: To gradually transition vehicles from one lane to another over a distance

A taper provides a gradual transition zone that allows drivers to merge or diverge smoothly and safely over an appropriate distance.

In roadway cross-section design, 'normal crown' refers to:

Answer: The standard two-sided cross slope on a tangent section

Normal crown is the standard cross-sectional shape with slopes falling away from the centerline on both sides to drain water off the roadway.

What is a 'frontage road' primarily designed to do?

Answer: Provide local access while separating local traffic from limited-access highway traffic

Frontage roads (service roads) run parallel to a limited-access highway, providing local property access while keeping that traffic off the main roadway.