Fellow Drivers that are using the bitless driving bridle, I would like to suggest that you make an important modification to common harnessing procedures when using the bitless bridle.
I would suggest that you NOT put your reins through the hame or neckstrap terrets. Because your rein buckle will be several inches closer to the terret than when attached to a bit, I believe there is a danger of the cross-under strap ring/rein buckle being able to slide up to and be stopped by the terret, and having your lateral control thus seriously diminished.
Secondly, there is an even greater danger, depending on the size of your collar terret, that the rein buckle and cross-under strap ring might actually pass THROUGH the terret, then become caught, trapping the horse's head to the side. This is a real danger, I have had it happen when a pair rein buckle passed through a saddle terret and became caught. I lost all control until the buckle finally freed itself, and we nearly had a tipover. As it was, my husband and dog were dumped out of the vehicle and into the river we were crossing at the time!
Thirdly, I believe that the usual position of the hame or neckstrap terret interferes with the action of the rein, and likely promotes an upheaded resistance to the noseband (pulling it backward on the face), whereas, a natural line from the mouth to the saddle terrets (similar position to rider's hands), would promote a more downward, break-at-the-poll response.
These comments are meant to be constructive, and not a criticism of the bridle.
Regards,
Barb Lee