Former Olympic cycling champion Chris Boardman says Heavy Goods Vehicles (HGVs) such as lorries should be banned from towns and cities during rush hour - to protect fellow cyclists.
He was speaking after a number of cyclists were killed by HGVs.
Lorry owners say the roads are for all to share.
But cyclists are 30 times more likely to be injured than motorists.
Our Correspondent Dan Rivers has been to Bristol to see how safe our roads are for cyclists.