My Garmin NUVI 1490 using the ESRI 12.0 map has the speeds showing down in the lower right corner. And, when out on some roads, the screen is split, speed on the left, speed limit on the right, then if going faster than the limit, the speed is in red. All well and good.

But, what is the speed limit?

For the Bangkok area Expressways it's 80 kmh, and red when exceeding that.

But for some highways, such as Hwy 4 to Ratchaburi, 1 to Saraburi, and 2 on to Korat, the speed limit is shown as 110 kpm! However the occasional speed limit sign on the side of the road still shows 90 as the speed limit.

Which is correct? Does ESRI know something the Thai Highway Police don't know?

Mac

Does the GPS also know what type of vehicle you are driving, as speed limits vary between say a sedan and a pick-up?

I think you would be well advised to ignore the displayed GPS speed limit. My Garmin also shows a speed limit of 110 kph while the road signs plainly show 90 kph.

Jack, mostly used in our Toyota HiAce van. Sometimes in our pickup, a 4-door, which got registered in the "sedan" category at higher annual registration tax, but is allowed to follow sedan rules.

Gary, agree, been mostly following the 90 kph rule. However the GPS was handy a few weeks back when I was stopped at the 2nd toll booth just past Don Muang, the baht 25 toll. Asked the ripoff cop what I'd done, he said 120 kph!! I laughed sort of politely in his face, pointed to the GPS and said "GPS," he sheepishly handed back my expired AAA IDP, and I motored on to Future Park.

Mac

Speed limit is 120 clicks outside the city

80 inside the city

Fine for speeding 500b

The avg person in the fast lane does 140

The outer ring-road is 120 except where otherwise marked; the main highways outside Bangkok (the Asian Highway or AH routes) are 110 except where otherwise marked. I drove 350km between downtown Bangkok and the north west of Nakhon Sawan province every week for 8 years until 2004 and nearly always got fined for speeding (deservedly) in both directions. I once asked a cop who pulled me as to the speed limit (this was on the Nakhon Sawan part of the Asian Highway) and was told that it was 110 but that the Nakhon Sawan police would not fine you unless you were doing over 117 ( I had previously believed the limit to be 90). I always asked a cop pulling me after that day as to how fast I had been driving – they ALWAYS said 118! I simply called them liars and refused to pay on the few occasions that I was not doing more than 117…and never had a problem.

Gotta ask, then, is there a miss-communication between the Highway Police and the sign painters who put up the LARGE signs giving speed limits and a profile of the type of vehicle they apply to? Still says 90 kph for sedans.

Is there anything in writing, Thai preferably, about the speed limits?

Mac

And on stretches of road whereby signed, those speeds apply. Similarly on the outer ring road: this is clearly marked as 120 for 4 wheeled traffic but there are numerous signs reducing this speed to 90, e.g. approaches to flyovers.