The call for heavy vehicles to be fitted with tachographs to track and record their speed and distance travelled is long overdue ("Curb speeding giants on road"; Tuesday).

Currently, light commercial vehicles, public transport vehicles and heavy commercial vehicles have different speed limits on the same road.

Are our static and manual speed cameras able to differentiate speed limits for different vehicle types and classes?

For instance, light commercial vehicles are limited to 70kmh on the expressways, while private vehicles can go up to 80kmh or 90kmh. However, I have seen the two types of vehicles travelling side by side at the higher speed limit.

In some cases, two similar vehicles can also have different speed limits if one is registered as a light commercial vehicle and the other as a private vehicle.

There are reasons why speed limits are applied to different types of vehicles - the most important of which is safety.

The difference in vehicles' mass and tyres affect the stopping distance and ability to negotiate road bends and curves.

It is common to see vehicles on our roads slipping and crashing into barriers or trees, or overturning on sharp bends, due to speeding.

The sooner tachographs are fitted in vehicles, the safer it will be for all road users.

Another belief speedsters have is that they can speed as long as their vehicles are blocked from the static cameras by a row of large vehicles, or if they drive on the extreme left lane of the expressway. I hope the authorities will also address this issue.

Ronnie Lim Ah Bee