CTE Intelligent Transportation Systems (ITS) 3

Question 1

What is the primary purpose of 'incident management' programs in transportation systems?

Accepted Answer

Detecting, responding to, and clearing traffic incidents quickly to restore normal traffic flow and reduce secondary crashes

Answer

Incident management programs — including Traffic Incident Management (TIM) — aim to reduce incident duration through rapid detection, quick clearance, and coordinated multi-agency response, restoring capacity and preventing secondary crashes.

Question 2

What is 'Cooperative Adaptive Cruise Control' (CACC) and how does it improve highway operations?

Accepted Answer

A connected vehicle application allowing platoons of vehicles to travel with shorter headways by wirelessly sharing acceleration/braking data

Answer

CACC uses V2V communication to allow following vehicles to respond immediately to lead vehicle speed changes, enabling shorter, stable following distances (headways) and more efficient traffic flow compared to standalone ACC.

Question 3

What is the 'probe vehicle' data collection method in traffic monitoring?

Accepted Answer

Using GPS-equipped vehicles in the traffic stream (fleet vehicles, smartphones) as anonymous sensors to measure travel time and speed across the network

Answer

Probe vehicle data leverages GPS-equipped vehicles — smartphones, commercial fleets, navigation apps — already traveling the network to measure real-time and historical travel times, speeds, and reliability across large geographic areas at low cost.

Question 4

What is 'managed lanes' technology and which ITS elements support their operation?

Accepted Answer

Lanes with operational controls — variable tolls, occupancy requirements, or access restrictions — supported by dynamic pricing systems, enforcement cameras, and variable message signs

Answer

Managed lanes use ITS tools — dynamic pricing algorithms, RFID/transponder toll systems, video enforcement, and DMS — to adjust access pricing or restrictions in real time, maintaining reliable travel speeds for users.

Question 5

In ITS, what does 'C-V2X' stand for and how does it differ from DSRC?

Accepted Answer

Cellular Vehicle-to-Everything; it uses LTE/5G cellular technology for V2X communication rather than dedicated DSRC spectrum

Answer

C-V2X (Cellular Vehicle-to-Everything) is an alternative V2X technology to DSRC that uses cellular networks (LTE-V2X, later 5G NR-V2X) for vehicle communications, supporting both direct device communication and network-assisted applications.

CTE - Certified Transportation Engineer Practice Test

CTE - Certified Transportation Engineer Practice Test

CTE Intelligent Transportation Systems (ITS) 3