I agree with Ron, but also I would say that troweling will seal and densify the surface making it less liable to shrinkage cracks following the brush finish. Good curing also a strict requirement.
We use Freson pattles on all our streets in the midwest, St. Louis specifically. It is generally 4 foot wide with a very thin surface. Here is a link from a google search:
Bridge slabs used to be longitudinally screeded, longitudinally belted, then broomed (sometimes even the broom finish was intentionally omitted). Either way, no trowel finish at all - results were a good looking, durable finish.