motorcyclists packed like sardines for as far as the eye could see in the motorcycle lanes along Woodlands Checkpoint Viaduct in Singapore... for the obscure reason that has nothing to do with motorcycles

 

My first thought was some biker protest, or biker funeral. 

Nope

the Singapore dollar had hit a record high of S$1 to the Malaysian Ringgit 3.57.

 According to Channel NewsAsia (CNA), the value was the lowest the Ringgit has reached since the 1998 Asian Financial Crisis.

So it's a currency exchange rate that caused a swarm. 

https://mustsharenews.com/woodlands-checkpoint-motorcyclists/