Thailand's capital prepared to host its twice-postponed annual auto show, with organisers saying it would showcase the country's success in containing the coronavirus.

From Detroit to Geneva, motor shows have been forced to cancel due to the COVID-19 pandemic, throwing the future of the industry's traditional way of marketing new models into doubt.

The 41st Bangkok International Motor Show opened to the public on Wednesday after being pushed back twice since March.

"This is more than the motor show, but also Thailand's reputation because the other event organizers will be watching," said Prachin Eamlumnow, chief executive of head organizer of the event, Grand Prix International.

Thailand will be the first to host a motor show on this scale since the pandemic, he told reporters.

Thailand has had no locally transmitted cases of COVID-19 for about seven weeks and has been easing restrictions imposed to tackle the outbreak, seeking to get its economy moving again.

The Southeast Asian country is a major regional car production hub, with its previous motor shows registering more than a million visitors.

Organisers have pledged to limit crowds this year and control entry at the show, where 25 car brands - including Ford and Subaru - and 22 motorcycle manufacturers will display their products.

Each brand's booth has entry and exit points and guests are required to scan a QR code, a type of barcode, with their mobile phones when entering and leaving, unlike at previous shows when people could roam freely.

Staff at the booths will also be wearing masks or face shields during the show, which runs from July 15 to July 26.

"The government allowed us to hold it, but we still must be very careful," said Prachin.