109. Traffic light signals and traffic signs.   You MUST   obey all traffic  light signals (download ‘Light signals controlling traffic’) and traffic  signs giving orders, including temporary signals & signs (download  ‘Traffic signs’). Make sure you know, understand and act on all  other traffic and information signs and road markings (download  ‘Road markings’ and Vehicle markings’) .  110. Flashing headlights.   Only flash your headlights to let other road  users know that you are there. Do not flash your headlights to  convey any other message or intimidate other road users.  111. Never assume that flashing headlights is a signal inviting you to  proceed. Use your own judgement and proceed carefully.  112. The horn.   Use only while your vehicle is moving and you need to  warn other road users of your presence. Never sound your horn  aggressively. You MUST NOT   use your horn  ● while stationary on the road  ● when driving in a built-up area between the hours of 11.30  pm and 7.00 am  except   when another road user poses a danger.  Law CUR reg 99  highwaycodeuk.co.uk 61  Laws RTA 1988 sect 36 & TSRGD regs 10, 15, 16, 25, 26, 27, 28, 29,  36, 38 & 40 