Cyclists are invisible to the eyes of taxi drivers? Hell no! Not when they take up a whole lane riding two or even three abreast! And when you need to turn left you have to slow down and follow them at their speed instead of overtaking them in case you kill the best friend of a forum owner.
There's nothing wrong with cyclists riding two abreast. It's legal in most countries and it's legal in Singapore. Motorists can easily overtake just as they would overtake a slower moving vehicle.
The problem has nothing to do with cyclists taking a lane. The problem is impatient motorists.
I once road from the Dempsey Road to Raffles Place and one stupid motorist taking the same route overtook me about 10 times along the way and GAINED NO TIME whatsoever. When I got to my destination, I was probably a minute ahead of him.
There is no point accelerating to 70 kph only to be overtaken time and time again by a cyclist doing 30 kph when the traffic slows to a standstill along the congested stretches.