Yeah, they are the same in the US, only metered when there is a lot of traffic. Which exacerbates the need for acceleration because you need not only match the speed before the ramp ends but also find a hole in the heavy traffic.

Why do you need to accelerate so much if the traffic is so slow?

Perhaps this is a cultural thing, but bad traffic here means stationary or less than walking speed. There is no need for hot rod acceleration in these situations!

Don't need to accelerate if the traffic is slow, need to accelerate if the traffic is heavy i.e. a lot of cars driving on the same road at 60-70 mph.