Even if your event is not to be held on a road or public highway, if you have a significant number of attendees the extra traffic could impact on the surrounding area. For instance if you have a long queue forming to enter the site to park. It would be the duty of the event organiser to manage this to ensure no detrimental impact is felt by the surrounding area.
The organiser would have to manage this with suitably trained and qualified staff or volunteers. On site traffic management would be included in this section. For example parking on site and how you organise both your staff, volunteers and event attendees to do it safely.
You will need to arrange public liability insurance for your event. The policy cover must be for a minimum indemnity sum of £5 million per incident. Please ensure your insurers are fully aware of all the activities taking place and that all your exhibitors, sub-contractors, caterers etc all have their own insurance. Evidence of this may be requested before, at or after the event.
My Community Starter is a free online resource for people who want to get involved in organising smaller, more straightforward community activities. It is a useful tool that is simple to use. It has links to all the relevant best practice and guidance on running events. There is a section on Insurance considerations and you have the option to purchase insurance direct from them.
Alternatively, insurance cover can be obtained through most local insurance brokers.