Emergency services were called after a car went up in flames.
Fire crews were called to Clos Bryngwili, close to the M4 flyover at Hendy, just after 4pm on Tuesday where the taxi was already engulfed by fire.
NHS Mental health support worker Aled Thomas who witnessed the fire said: "I noticed the smoke from the M4 as I was coming off at Hendy junction and then the smell of burning rubber hit me like a slap in the face."
Mid and West Wales Fire and Rescue Service said they used a hose reel jet to extinguish the blaze. They left the scene by 4.49pm.
Officers from Dyfed-Powys Police also attended the incident.
A spokesman for the force said their attendance was for traffic management reasons and the incident was not being treated as suspicious.
