Knock, Knock

Knock, knock.
Who's there?
Isabel.
Isabel who?
Is a bell necessary on a bicycle?

To test this we edited together all the times we used our bell on the way to work today. They are:
Van pulling out, overtaking a cyclist, overtaking a cyclist, jaywalkers, pedestrian in the road, pedestrian in the road, scooters and cyclists rubbernecking a cop giving a ticket, van reversing into traffic, pedestrian in the cycle lane, scooters trying to jump a red light, overtaking a cyclist, overtaking sporty kid on a bike who can't believe a forty-something white guy is going faster than him, scooters jumping a red light, two cars and a scooter turning into oncoming traffic, scooter coming out of the sun on the wrong side of the road, a wheelchair and two more jaywalkers.

Isabel necessary on a bicycle? She certainly is!