NETTCP Traffic Management & Control Systems 5

Question 1

A traffic engineer is reviewing detector occupancy data and notices values consistently above 80%. This most likely indicates:

Accepted Answer

Highly congested or stopped traffic over the detector

Answer

High occupancy percentages mean vehicles are sitting over the detector for long periods, which is characteristic of stop-and-go or queued traffic.

Question 2

In signal timing design, the 'lost time' per phase accounts for:

Accepted Answer

Start-up lost time and clearance lost time during which the intersection is not efficiently used

Answer

Lost time includes start-up delay as queued vehicles react and clearance time during the yellow and all-red, representing time the phase is not fully productive.

Question 3

Which technology allows a traffic management center to remotely adjust signal timing plans without a technician visiting the cabinet?

Accepted Answer

Central signal control via fiber optic or wireless communication network

Answer

A central signal control system communicates with field controllers over a network, enabling operators to push updated timing plans remotely.

Question 4

What is the primary reason for using a 'lag left-turn' phase instead of a 'lead left-turn' phase at a signalized intersection?

Accepted Answer

A lag phase can reduce the overall cycle length and improve operations in certain traffic conditions

Answer

A lag left-turn phase occurs after the opposing through movement, which can reduce cycle length and improve coordination under certain demand patterns.

Question 5

In New England states, winter maintenance operations often require coordination with traffic management because:

Accepted Answer

Plowing and anti-icing activities affect detector accuracy and require adjusted signal timing or worker protection plans

Answer

Snow and ice can cover loop detectors and alter traffic patterns, requiring recalibration of detection and work zone signal plans to protect maintenance crews.

(NETTCP) New England Transportation Technician Certification Program Practice Test

(NETTCP) New England Transportation Technician Certification Program Practice Test

NETTCP Traffic Management & Control Systems 5