CME Transportation Engineering & Traffic Management Flashcards

What does the 85th percentile speed represent in traffic engineering?

Answer: The speed below which 85% of vehicles travel

The 85th percentile speed is the speed at or below which 85% of vehicles are traveling, commonly used to set posted speed limits.

Which pavement design method is most widely used for flexible pavement in US municipal streets?

Answer: AASHTO pavement design method

The AASHTO pavement design method, based on the AASHO Road Test, is the most widely adopted approach for flexible pavement design in the US.

What is a roundabout's primary safety advantage over a signalized intersection?

Answer: Elimination of high-speed right-angle and head-on conflicts

Roundabouts eliminate the most severe crash types—right-angle and head-on collisions—by converting all conflicts to lower-speed merging movements.

What is the function of a 'shy distance' in roadway cross-section design?

Answer: Lateral clearance buffer between travel lane edge and fixed objects that affects driver behavior

Shy distance is the lateral clearance needed beyond a travel lane edge to prevent drivers from instinctively moving away from nearby fixed objects.

Which federal act requires municipalities to consider Title VI equity impacts in transportation planning?

Answer: Civil Rights Act of 1964 (Title VI)

Title VI of the Civil Rights Act prohibits discrimination in federally funded programs, requiring transportation agencies to assess impacts on minority and low-income populations.

What type of intersection control is typically recommended when peak-hour traffic volumes on the minor road are very low compared to the major road?

Answer: Two-way stop control (TWSC)

Two-way stop control is appropriate when the major road has significantly higher volumes than the minor road, minimizing delay for the predominant traffic flow.