I live in the north in YCK area.
I think the roads in singapore is not that bad and we can support more vehicles. The only problems are the expressways, namely CTE and PIE.
I think if they bothered to build the N-S expressway announced in 2008, it would solve a lot of problems as the traffic from woodlands and AMK gets routed into another expressway away from CTE. Having another NS expressway will remove the Jam at the PIE CTE junction as there is another way towards the city.
The problem is that the government just collect money from CTE ERP for soo many years but never did anything, until recently.