Hi Mohammad Abu Sayeed! In Singapore, it's illegal to make U-turns where there is no sign that says so. This is dangerous because drivers may make this mistake at right-turning corners where they may come in collision with other vehicles heading their direction. Offenders are not awarded with demerit points, however, it will be fined $100 for this simple violation. More details can be found here: https://www.motorist.sg/article/534/traffic-offences-in-singapore-demerit-points-composition-fines-2022-update