Point to Point auto reversing track set: B/B tracks not used

[REID2012]

I just bought the above set and a trolley. I set up the track as instructed with the A/B track connected to the B/B track and that connected to the bumper at each end.
When I run the trolley it stops and reverses at the A/B track at each end and does not go onto the B/B track or to the bumper.
Is this the way it should work?

[Hunt]

Yes, it is working as it should.

[REID2012]

Thanks. What is the purpose of the B/B tracks and the bumper?

[Hunt]

B/B track to accommodate car(s) connected to motorized unit. Bumper mainly for looks but will block over run.   

[REID2012]

Thanks again