Arlington Park alternate finish line
 

I've seen Arlington use the alternate finish line or short stretch for their 1m 1/16th races in the past. Does anyone know if they still occasionally use it and under what circumstances? Did they use it at all in 2016?

They do it every time they run a 1 1/16 mile dirt race (see also Gulfstream). Conceivably they could also use it to run 7 1/2 furlongs on turf, but so far they haven't.

The first race yesterday was at 1 1/16m and they finished at the regular finish line. I'm guessing they're not using the other line this year.

This isn't correct. The alternate finish is used based on the number of horses to run in the 1 1/16m races. I believe it is 9 or more horses to race and they will use the alternate finish. This is why race 1(6 horses)and race 4(8 horses) and race 5(8 horses)yesterday didn't use the alternate finish but race 8(12 horses)did.

Yes they will be using it, see my above post.