None of my colleagues could put a finger on the cause, and as people will, we fell to guessing.

One guess was Suvarnabhumi Airport.

It was the second day it had been officially open, and it must, we mused, be thronged with passengers plus their friends and relatives, scouting it out before their scheduled flights like luk thung singer Arpaporn Nakhonsawan, who ranks it second to none in terms of design and function - and he's a travelled man.

Indeed, chaotic moments apart, many Thais are proud of their new airport. Nor are they alone: the Taiwanese press also gave a great deal of coverage to Thursday's launch of Suvarnabhumi, one of the biggest airports in Asia.

We have reason to be proud too: Suvarnabhumi's annual passenger capacity is 45 million, compared to 46 million for Changi Airport in Singapore, 45 million for Hong Kong International Airport, 45 million for Kuala Lumpur International Airport and three million for Incheon International Airport in South Korea.

Yet there are five routes in and out of the airport: it could not be causing the jam.

One possibility was nearby flooding causing motorists to slow down.

But my favourite was the simple fact that Thailand is still a poor country.

Simple? Look at it this way: that Friday was salary day, and traffic on salary day is always jammed. Taxi-drivers say they earn most of their money during the first two weeks of each month when passengers can afford to take cabs. Shopping centres are full on salary day too, when people come to buy the items they have had their eyes on for some time or to dine out at stylish restaurants there.

Unlike the wealthy, to whom shopping and lavish dining can be a daily routine, the end of the month is when salaried workers splash out.

It might be better for them and for the country if they saved some money for the middle of the month - it would certainly ease the end-of-the-month traffic congestion - but it is hard to tell them so, given that some of them are down to a few hundred baht by salary day.

So the vicious cycle remains. Think what you will, they still pay their taxes regularly, which may explain why many of them grind their teeth when they see rich men under-taxed.

achara_d@nationgroup.com