Since Monday, car drivers and passengers passing through the land checkpoints have had to step out of their vehicles to have their thumbprints scanned to clear immigration.

It is the latest push towards a full implementation of the BioScreen system, launched in April last year to boost security at the borders.

The system is in place at various clearance zones at the Tuas and Woodlands checkpoints for train and bus travellers. Such travellers have their prints scanned while going through manned immigration counters.

But extending this to car users could be challenging, with several concerns already highlighted in the early days of the trial.

The authorities have said that Singaporeans who use the automated clearance lanes at land, sea and air checkpoints will not be affected.

With automated clearance lanes not available for car users at the moment, all those above six years old will have to take this extra step, regardless of their nationality.

Some have pointed out the inconvenience it may cause for elderly and disabled passengers, who may not be able to get out of the car easily.

Others have questioned whether this would result in a build-up of traffic and even longer waiting times.

Capturing the thumbprints of visitors arriving and departing at the checkpoints will allow the authorities to verify identities and spot potential security risks early.

This is crucial in the Republic's efforts to confront the worldwide threat of terrorism at home.

After all, Singapore's land checkpoints are among the busiest in the world, with more than 400,000 crossings daily. Travelling across the border by car has always been a popular choice as well.

Travellers could find it a hassle and public opinion may be unsympathetic during the early phase of the BioScreen system, but national security has to remain a priority, especially in the challenging times ahead.