In the last 20 years schools have become mini-fortresses – but our children are still at risk.

Ever since Thomas Hamilton walked into Dunblane primary and shot dead 15 children and a teacher, security has become paramount. Fences, gates, locks, cameras, security doors keep children safe inside. It's when they get outside the trouble starts – and all because of the parents. The biggest danger comes from whoever's doing the school run.

It's so bad that last week the president of the National Association of Head Teachers said parents' bad parking is putting their children's lives at risk.

We've all seen it. Go past any school at the start or end of the school day and you'll find cars parked higgledy-piggledy, blocking entrances, obstructing traffic, restricting views. Queues build up while everyone waits for children to scramble out, not forgetting their lunch boxes, sports kit, violin and those enormous back-packs... it takes time.

Any child actually walking to school will often have to step off the pavement because it's blocked by cars.

Some parents double park and then let their children out straight into the traffic. They think they're being a little bit cheeky. In fact they're being spectacularly stupid. No wonder nearly 1,200 children a month are involved in accidents near the school gates. Not yours? – yet.

Some schools are getting tough on inconsiderate and dangerous parking – even experimenting with road closures. Police have occasional blitzes. Headteachers and doctors plead with parents to let children walk to school.

But, let's face it, it's not going to happen.

Previous generations all walked to school unaccompanied, often long distances. But the world has changed. Parents are in a hurry, have work to go to and expect to drive everywhere. Roads are busier – and not just because of the school run – and children are less independent.

You wouldn't build a supermarket now without a car park. Maybe we should do the same for schools. Or at least organise an airport-style circular drop off point so cars can drive straight through without chaotic manoeuvres. Walking to school is brilliant for all sorts of reasons, not least independence, but, sadly, it's a thing of the past. It's time to face the world as it is, not as we'd like it to be – and that means accepting the school run and making it safe.