Make cars without signal lights

The way Singaporean drivers drive, cars should be made without signal lights. After all, why put in a feature that is not used by 90% of the users? I am sure most of you out there who drive in Singapore (or ride, for that matter) know what I am talking about. Drivers changing lanes without giving any form of signals, or signalling just as they are changing lanes. There are also drivers who turn without signalling. Cars were built with signal lights so that people can let others know their intentions (change lanes, turn, stop at the side of the road, etc.) but if people are not going to observe these simple basic rules, our roads will never be a safe place. Anyway, I wonder if cars come cheaper without signal lights...