85: Signals warn and inform other road users, including pedestrians (see Signals to other road users section), of your intended actions. You should

• give clear signals in plenty of time, having checked it is not misleading to signal at that time
• use them, if necessary, before changing course or direction, stopping or moving off
• cancel them after use
• make sure your signals will not confuse others. If, for instance you want to stop after a side road, do not signal until you are passing the road. If you signal earlier it may give the impression that you intend to turn into the road. Your brake lights will warn traffic behind you that you are slowing down
• use an arm signal to emphasise or reinforce your signal if necessary. Remember that signalling does not give you priority.

86: You should also

• watch out for signals given by other road users and proceed only when you are satisfied that it is safe
• be aware that an indicator on another vehicle may not have been cancelled.

87: You MUST obey signals given by police officers and traffic wardens (see Signals by authorised persons section) and signs used by school crossing patrols.
Laws RTRA sect 28, RTA 1988 sect 35 and FTWO art 3

88: You MUST obey all traffic light signals (see Light signals controlling traffic section) and traffic signs giving orders, including temporary signals & signs (see Traffic signs and Road works signs sections) . Make sure you know, understand and act on all other traffic and information signs and road markings (see sections on Warning signs, Direction signs, Information signs,Road works signs and Road markings).
Laws RTA 1988 sect.36, TSRGD regs 10,15, 16, 25, 26, 27, 28, 29, 36, 38 & 40

89: Police stopping procedures. If the police want to stop your vehicle they will, where possible, attract your attention by

• flashing blue lights or headlights or sounding their siren or horn
• directing you to pull over to the side by pointing and/or using the left indicator.

90: Flashing headlights. Only flash your headlights to let other road users know that you are there. Do not flash your headlights in an attempt to intimidate other road users.

91: If another driver flashes his headlights never assume that it is a signal to go. Use your own judgement and proceed carefully.

92: 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