What is the correct procedure for merging onto an expressway from an on-ramp in Singapore?

1. Adjust speed to match the expressway traffic flow and merge smoothly using the acceleration lane, giving way to vehicles already on the expressway
2. Come to a complete stop at the end of the ramp and wait for a gap
3. Flash headlights to signal vehicles on the expressway to slow down
4. Merge immediately onto the expressway regardless of traffic speed