Examkin

Question

Difficulty: MediumSmart Motorways and Active Traffic Management

On a smart motorway, an overhead gantry displays a speed limit of 50 mph inside a red ring above your lane, although the motorway ahead appears completely clear. What action must you take?

  1. A
    Maintain the national speed limit because variable speed limits are purely advisory when traffic flows freely
  2. Comply with the 50 mph speed limit because speed limits displayed inside a red ring are legally mandatoryAnswer
  3. C
    Ignore the gantry display until you observe physical roadworks or a stationary hazard ahead
  4. D
    Match the speed of the vehicle directly ahead regardless of the overhead gantry display

Answer

Comply with the 50 mph speed limit because speed limits displayed inside a red ring are legally mandatory.
On smart motorways, speed limits displayed within a red circle are mandatory and legally binding. They are set dynamically by active traffic management systems to smooth congestion, prevent tailbacks, or manage unseen hazards further ahead. Drivers must obey them even if the immediate road ahead appears completely clear.

Step-by-Step Solution

1
Identify the shape and border of the overhead gantry speed display
Recognised that the number 50 is displayed inside a solid red circular ring
Circular signs with red borders convey mandatory orders and legal prohibitions under the UK Highway Code
2
Apply the rule for smart motorway Variable Speed Limits (VSLs)
Determined that the 50 mph limit is legally enforceable regardless of visible traffic volume or weather conditions
Smart motorway systems automatically adjust speed limits to smooth traffic flow and manage downstream incidents before they become visible
3
Select the driving behaviour that fulfills legal compliance
Adjust vehicle speed so as not to exceed 50 mph until a different limit or the national speed limit sign is displayed
Failure to obey a mandatory variable speed limit is a legal offence enforced by speed cameras

Key Concept

Mandatory Variable Speed Limits on Smart Motorways
Estimated Time:45s
Rate this question

Topics

Smart Motorways and Active Traffic Management

More questions from this topic