How does a Guide Dog know when to cross the road?

I got a message from on of my Twitter pals, @Snick_the_dog recently. Here's what he had to say:

@GD_Kenworth,
Mom wonders how Guide Dogs know when to cross the street. I would run into traffic if Mom didn't stop me. I am too impatient!

Well, Snickers, to be honest, I get a little impatient sometimes too. You see, I'm not actually allowed to say 'GO' to cross roads, only 'STOP' when it isn't safe. Sometimes I think My Person takes FOREVER to say 'forward'!

It's up to My Person to assess the traffic conditions and decide when she thinks it's safe for us to cross. She gives me the 'foward' command when she thinks it's all OK. I'm allowed to say no (by not moving foward) if there's a car or something dangerous. This is called intelligent disobedience.

I found this picture of my cousin, GD_Keegan, when he was in training.

As you can see, the instructor has his arm back. This is the start of the hand movement that goes with the 'forward' command. The instructor is waiting for the truck to be close enough to be a threat, then he'll give the 'forward' command. If Keegan doesn't move, he gets lots of praise (and is told 'when you can', so he can choose to go when the truck is past, if the road is then clear). If Keegan steps at all, the instructor would pull back on the harness sharply and say 'NO'. Most of us learn pretty quickly that stepping out when there's a car that close only leads to getting in trouble.

It does help that we've been having to stop at roads all our lives - our puppy raisers never cross a road without stopping. We are also not supposed to walk in front of (or behind) a car with the engine running EVER.

So how does My Person tell if it's safe to cross? She looks (as she is not totally blind she uses what sight she has) and she listens. On quiet streets this isn't too hard - hear a car and figure out where it's coming from. On busier roads it's harder. We always try to cross at traffic lights or intersections. If there aren't audio signals for the crossing, My Person can use 'parallel traffic' to give her clues. If traffic is going accross the intersection in the same way she wants to cross, it should be safe.

Sometimes we Guide Dogs do make mistakes - which is why our People need to make the judgement and stay aware of what the traffic is doing. Road crossing safety for Guide Dogs and their handlers is a matter of continual reinforcement - if My Person thinks I'm cutting things too fine (and she tests me on it sometimes) she lets me know I've chosen wrong and won't cross the road. I'm usually pretty good at it, though!

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Thanks for such a good question, Snickers!

Questions? Comments? I'm looking for my next question, folks - comment me your ideas!