In August of this year, Alex Paxton was cycling along Fulham High Street in London. He came to the front of a queue of traffic waiting to turn right and found the box reserved for cyclists to be occupied by a car.

He did what I believe most cyclists would have done in the circumstances, and he stopped ahead of the cycle box in front of the driver. He had approached the junction in the middle lane, which was for traffic going straight on, for which a green light was showing. So, he could not simply have come to a stop in the cycle box in that lane.

When the light went green he turned right and was stopped by a police officer who gave him a fixed penalty notice for crossing the Advanced Stop Line (ASL) on a red light. It is unclear whether the motorist who had encroached on the ASL was given a fine. However, rule 178 of the Highway Code prohibits motorists from doing so unless they had proceeded into the cycle box when the light was green and then come to a stop when the signal went red.

Paxton was understandably frustrated by the police officer's decision to give him the fine and sought advice from the Cycling Defence Fund - a charity which helps cyclists to fight legal cases. They agreed that the fine was unreasonable and started a JustGiving page, raising £2,500 from individual donors to support his case. The Cycling Defence Fund referred him to me and I provided some advice on a pro bono basis, and helped him to instruct a barrister.

The trial was due to go ahead this week, but the Crown Prosecution Service has now confirmed that the proceedings against him will be discontinued. This is, of course, great news for Alex Paxton and for cyclists in general. However, it is disappointing that the police took this action in the first place, which required a committed cyclist, a grassroots campaign group and the generosity of the donors to get what is surely a common sense result.

Approximately 75% of collisions involving cyclists happen at, or near, a road junction. The purpose of an ASL is to reduce the number of collisions by creating a buffer between cyclists and the motor traffic behind, and to make cyclist more visible at junctions.

Currently the law adopts the same inflexible rules for bikes crossing ASLs as for motorists, when the threat posed by cyclists is far lower. Cyclists are also vulnerable road users who may act in a less predictable way to protect themselves. There is currently no legal guidance to clarify what a cyclist should do if stopping in the ASL is hazardous, as was the case for Alex Paxton.

As a result of the recent deaths of six cyclists in London, the police introduced Operation Safeway. Superintendent Rob Revill said the aim was

"to reduce the appalling number of people who die or are injured on London's roads each year....by enforcing traffic legislation robustly."

This sounded promising but the police have been issuing fixed-penalty notices of £50 to cyclists who have infringed traffic rules. It has now been established that Operation Safeway gave police officers a target to fine 10 cyclists per month for road traffic offences.

Naturally cyclists should be expected to uphold the law, but in reality the harm flowing from their infractions is minimal. It is worrying that a police force looking to aggressively reduce the number of cycling deaths thinks that targeting cyclists is the answer.

To make the roads genuinely safer the focus must shift beyond the low-hanging fruit and police need to take a hard line on statistically proven dangers. Speeding motorists are shown to be one of the biggest causes of deaths and serious injuries, yet the Association of Chief Police Officers (ACPO) have only recently undertaken to change their position that 20 mph zones should be self-enforcing, with no expectation on the police to provide additional enforcement beyond their routine activity.

To genuinely reduce the risk of injury to cyclists, the police need to start taking a proportionate approach to law enforcement, as they failed to do in Alex Paxton's case.

• Oliver Jeffcott is an associate solicitor at Bolt Burdon Kemp and a keen cyclist. He blogs as The Cycling Solicitor.