Traffic Engineering MCQ with answer and solution

Concept

Equipment for automatic traffic volume counts

Formula

NONE

Step-by-step solution

1. Traffic volume counts can be conducted manually or by using automated mechanical tools. 2. Pneumatic tubes laid across a road segment detect passing vehicle axles automatically via air pressure impulses. 3. Therefore, pneumatic tubes belong to the class of automatic devices. Answer: C

Explanation

Pneumatic tubes are flexible rubber hoses stretched across a roadway that record air pressure pulses whenever vehicle axles pass over them. These pulses send electrical signals to an automatic roadside counter, allowing continuous traffic volume measurement without manual supervision. Therefore, this equipment is classified under automatic devices.

Why the other options are wrong

A) Manual counts rely on human enumerators directly recording passing traffic. B) Combination methods use human observers alongside simple tally counters rather than pneumatic tube detectors. D) Photographic methods use cameras and video recording to capture traffic data.

Shortcut

Pneumatic tubes detect air pressure pulses automatically (Automatic devices).

Common mistake

Classifying pneumatic tubes under combined manual and mechanical methods rather than automatic devices.