One of our customers encountered a bottleneck doing lane numbering.

Given a binary parameter bp_laneExists( i_locFrom, i_locTo ), can you efficiently number the lanes?

The essence of their code looked as follows:
 

As you can see, on my laptop this loop takes ~14 sec.

I was able to reduce the dimension by one with the following code:

As you can see, on my laptop this loop takes ~1.7 sec.

Please find my sample project enclosed.