From the top of the Valleys, the A470 does the work: Merthyr to Cardiff Gate in around 40 minutes, dual carriageway most of the way, parking when you arrive. It is the longest regular journey on this page and Merthyr clients tell us it earns its keep twice over, once for the answer and once for the distance from home.
The pattern of work from Merthyr matches the rest of South Wales: fidelity questions ahead of everything else, then family disputes, then employers who need a theft investigation done properly rather than loudly. Every examination follows the same protocol regardless: the question agreed in exact words first, nothing recorded until it is.
By car: A470 south, around 40 minutes from Merthyr to Cardiff Gate, just off M4 junction 30. Onsite parking.
By train: Merthyr Tydfil to Cardiff Central takes about an hour, then a short taxi to the office.
Recommended office: Our Cardiff Gate office, straight down the A470. Exact directions are sent with your booking confirmation.
One visit covers everything: pre-test interview, the examination and the same-day preliminary result, usually inside two hours on site. The full written report with charts arrives by secure delivery within 24 hours, so there is nothing to return for.
Then no test happens, because consent given under pressure invalidates the result and we will not proceed without it. It is rarer than you might fear: most people who make the journey down the A470 have decided they want the matter finished.
The nearest permanently run polygraph office to Merthyr is ours at Cardiff Gate, a straight run down the A470 and briefly onto the M4, about forty minutes with parking onsite. For the Heads of the Valleys that makes Cardiff the practical answer to a near-me search, and the journey buys you a controlled examination room rather than a space borrowed for the day.
By car to Cardiff Gate: M4 westbound, junction 28 to junction 30
By car: M4 eastbound to junction 30, around 50 minutes from Swansea
By car: M4 junction 35 to junction 30, around 25 minutes
By car: A4232 to the M4, then east to junction 30. Around 30 minutes from Barry with onsite parking
By car: A468 or over the mountain to junction 30, around 20 minutes from Caerphilly town centre
By car: A470 south then A48 east to Cardiff Gate, around 25 minutes from Pontypridd. Onsite parking
Our Chepstow office is at Riverside Court, Beaufort Park, Chepstow NP16 5UH, with parking on site
Services, prices, our examiners and live availability.
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