I ask this as we live on a street of Victorian terraces, all of the houses just have a small yard but no gardens. Because of this the kids play on the back street. It is a quiet street, but cars do occassionally come down - normally residents who park at the back, so normally driving slowly.
My ds (4) is desperate to play with the bigger kids (most are 6-10 yrs) but there are a few 4/5 year olds. I ket my ds out if I am in the yard reading/gardening etc but dh does not let him out at all.
Just wondered what everyone else does.