Traffic Engineer Interview Questions UK: 8 Real Questions and What Interviewers Want

Applying for a Traffic Engineer job in the UK? Here is what you are likely to be asked. These questions come from our Traffic Engineer question bank of 12 questions, written for UK employers at mid-level level.

Eight Traffic Engineer interview questions, and what the interviewer is thinking

1. How would you assess the traffic impact of a proposed development, and what documents would you produce?

Why they ask: Transport assessment is the bread and butter of traffic engineering.

2. What does a traffic engineer do day to day, and what attracted you to the profession?

Why they ask: Tests understanding and genuine motivation.

3. Explain how a signalised junction works, and how you would optimise its timings.

Why they ask: Signal design is a core specialism.

4. What is the difference between a priority junction, a roundabout and a signalised junction, and how do you decide which to propose?

Why they ask: Junction selection is a classic question.

5. Residents complain that a new zebra crossing has caused queues and they want it removed, while the school says it is essential. How do you handle it?

Why they ask: Tests stakeholder balancing and evidence-based thinking.

6. Tell me about a time you used data to solve a traffic or road safety problem.

Why they ask: Evidence-led problem solving is key for the role.

7. What are the key considerations when designing for cyclists and pedestrians on a highway scheme under current UK guidance?

Why they ask: Active travel design is now central to the profession.

8. A road safety audit of your design identifies a serious problem you disagree with. What do you do?

Why they ask: Tests professionalism around independent review.

A sample answer to question 1

How would you assess the traffic impact of a proposed development, and what documents would you produce?

I would begin with scoping, agreeing the study area, junctions, assessment years and growth assumptions with the local highway authority and National Highways if the strategic road network is affected. I would collect baseline data through traffic counts, queue length surveys and speed data, and check collision history over five years from the police STATS19 data. Then I estimate trip generation using TRICS, using sites comparable in size, location and accessibility, and distribute the trips using census journey to work data or gravity models. I assess junction performance with software such as LinSig, Junctions 10 or Vissim, reporting ratio of flow to capacity, queues and delays for baseline and with-development scenarios. Depending on size, I produce a Transport Statement or a Transport Assessment, as set out in the National Planning Policy Framework, along with a Travel Plan and a framework for mitigation. I also consider walking, cycling and public transport, because the NPPF requires a vision-led approach rather than just capacity.

Common mistake to avoid: Looking only at capacity; Not agreeing methodology beforehand

Want the rest?

Full model answers, key points and common mistakes for all 12 questions are on the Traffic Engineer interview questions page. The first five are free, no sign-up needed.