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.
The driver convicted of driving offences after she tweeted about "bloody cyclists" following a collision said she "did not think" the cyclist was injured.
Emma Way told Norwich Magistrates' Court she had lived near the road where the collision took place for 20 years and had cycled along it as a child.
Claiming the incident was cyclist Toby Hockley's fault, Way said she had been driving at 15mph and her road positioning was as far to the nearside as possible.
"Afterwards I looked in my mirror," she continued. "I did not think he was injured - if I did I would definitely have stopped."
Motorist Emma Way was fined £337 and ordered to pay £300 costs after being convicted of failing to stop and failing to report an accident.
Way collided with cyclist Toby Hockley in Norfolk in May and later tweeted about the incident.
Magistrate Martin Cliffe also ordered that seven penalty points be added to her licence.
Way told the court that she had lost her job with Norwich-based accountancy firm Larking Gowen as a result of the tweet.
She said: "The tweet was spur of the moment. It was ridiculous and stupid and I apologise to all cyclists. It is the biggest regret of my life so far."
A motorist who tweeted about "bloody cyclists" after a collision described the post as "my biggest regret" as she was convicted of driving offences.
Former trainee accountant Emma Way, 22, from Watton, Norfolk, was found guilty at Norwich Magistrates' Court today of failing to stop after a collision and failing to report an accident.She was cleared of driving without due care and attention.
Magistrates heard police only became aware of the collision on May 19 because Miss Way tweeted "definitely knocked a cyclist off his bike earlier. I have right of way - he doesn't even pay road tax!" using the hashtag #bloodycyclists afterwards.
Cyclist Toby Hockley suffered bruising and minor damage to his bike in the incident near the village of Rockland All Saints, Norfolk.
Motorist Emma Way, who tweeted about "bloody cyclists" following a collision, has been convicted of two driving offences including failing to stop and failing to report an accident at Norwich Magistrates' Court today. She was cleared of driving without due care and attention
Police investigating the death of a cyclist in Whitechapel have identified the victim.
However, police said the 21-year-old man would not be named ahead of the inquest into his death at Poplar Coroner's Court.
The 21-year-old died after colliding with a double decker bus at a busy junction in east London on Wednesday.
Police said they were continuing their enquiries but no arrests had yet been made.
The man was one of five cyclists who died in just nine days in London, during a spate of accidents in the capital last week.
Guide for cyclists and motorists from Transport for LondonRead the full story ›
Police have also named the cyclist killed in a collision with a bus in East Croydon on Tuesday. 43-year-old Roger William De Klerk was an IT consultant and courier from Forest Hill.
The Met Police said: "A post-mortem examination has taken place and gave the cause of death as compression of the head, neck and chest."
A lawyer who has represented a number of victims of cycle accidents is demanding an independent inquiry after to help uncover why there have been so many deaths.
The time to act is now. I have represented cycle victims over many years; the situation is not getting any better, it is getting very much worse. It is no surprise that with a lack of the most basic infrastructure on London streets that as the darker nights draw in the death toll is climbing. I am writing today to Boris Johnson's office demanding an Independent Review on behalf of so many of my clients who have suffered life altering injuries.
It is of note that so many HGV vehicles in London still do not comply with the necessary safety recommendations that are known to be crucial in the fight against such deaths. I have clients where the injury was caused because the vehicle did not have the correct mirrors or even if they did the were not used properly. But putting cyclists so close in proximity to HGV's and buses is surely the most basic flaw of all.