easement

[HFS082]

I have an easement over my neighbour's land giving me access to the public highway. It gives me and my successors in title, owners or occupiers of my property the right "to pass and repass with or without motor cars or other vehicles over and along the road coloured green on the said plan from and to the highway aforesaid and to and from the Property"
My neighbour has since built on his property and and also allowed another adjacent property owner to use the common access. The owner and the new user have taken to parking vehicles on the right of way, and allowing visiting tradesmen to park vans etc. This effectively narrows the access so as to completely prohibit the passage of commercial vehicles to my business, and making even car access for my family difficult.
Has my neighbour got a duty to maintain the right of way clear of obstructions? Does a parked vehicle count as an obstruction, and what can I do to ensure my right of way remains the full width in accordance with the plan on my deed?

[HomeGuru]

By your writings I presume that you are not in the US. If that is the case, I can not advise you because this webite deals with US law and not the laws of any other country.
Hopefully your country has a similar free law advice website.