I've taken my Khiva alongside the bike on days when I'm feeling too lazy to run with her. Keep in mind that we've put in hundreds of miles together so she's very used to the leash and my direction. So it can be done if you're confident in your dog's on-leash behavior.
But I would never take her along a busy highway. That just seems way too risky for both canine and human.
As to your question, how far? Probably as far as you want to go. Weren't Dalmatians team dogs that would trot along with the horses pulling wagons? If the weather was cool, probably 10 miles. Of course YMMV.