The school holidays have been in full swing here in Scotland for a few weeks. I drove to our local shopping precinct yesterday and had a few close shaves with boys on bikes (aged around 8 to 12) swooping on and off the pavement. If your DCs are out on bikes this summer please encourage them to stick to the rules - indicate what they intend to do and give drivers a chance to react.
One further plea - consider bike helmets, please. Our older DS had an accident on his bike when we was 14 - skidded in gravel and hit a viaduct. He was in hospital for a few days but made a full recovery - broken teeth were the worst thing. He had a helmet on (at my insistence) and the doctors said this probably saved him from brain damage - and possibly from being killed. You won't be popular if you make your DCs wear helmets - they are not "cool" - but you might just save their lives.