Know what your mirrors cannot show
A blind spot is an area outside the view provided by your mirrors. A road user can be nearby even when the mirror appears empty. Observation therefore combines mirrors with an appropriate direct check, while keeping control of the vehicle and attention to the road ahead.
Before a journey, set up your driving position and make sure the mirrors are clean and properly adjusted. Ireland's Road Safety Authority guide explains these preparations and the need for all-round observation before moving off. Learn the checking technique in your own vehicle with your instructor; memorising a head movement without understanding its purpose is not enough.
Situation 1: Moving out from a parked position
The mirror looks clear
You are stationary beside the kerb, preparing to join traffic. A delivery van blocks part of your rearward view. Your interior mirror shows no approaching car. Is that enough information to move?
Check your reasoning
Stay stationary until you have checked the relevant areas and found a safe opportunity. The empty interior mirror does not describe the space alongside the car, behind the obstruction or in a blind spot. Consider a cyclist or motorcycle approaching beside you, as well as other traffic.
Use the mirrors and appropriate direct checks; signal as required locally and make a final observation before moving. If the delay is long enough for traffic to change, refresh the information. A signal communicates an intention and does not clear the space you intend to enter. The British Highway Code, rules 159 and 161, describes mirror and blind-spot checks before moving off.
For revision, finish this sentence: “I am waiting because I have not yet checked…” Naming the missing information helps you distinguish a real safety decision from simply choosing the most cautious-sounding answer.
Situation 2: A vehicle disappears from view
A motorcycle was behind you
You intend to change lane where signs and markings permit it. A motorcycle you noticed earlier is no longer in the mirror. The destination lane looks empty in the part you can see. Should you assume it has turned away?
Check your reasoning
No. Its position is uncertain. It may be alongside you outside the mirror's view. Keep your course while checking rather than starting the lane change to obtain a better view. Reassess the gap and the movement of traffic before deciding whether to proceed.
The Danish category B curriculum, section 7.4.3, specifically includes hidden rearward traffic, mirror checks, head-turn checks and judging the available gap. Do not treat a lane change and a merge as identical legal situations: the applicable markings and local rules still matter.
The useful observation is the motorcycle's changing position relative to your intended path. Remembering that it was behind you several seconds ago does not establish where it is now.
Situation 3: A cyclist beside a Danish junction
You plan to turn across a cycle track
On a Danish road, you are approaching a right turn beside a cycle track. You saw a cyclist earlier, but a passenger-seat head restraint now hides part of your side view. Your traffic light turns green. Does the light resolve the observation problem?
Check your reasoning
No. You still need to locate the cyclist and check the path you will cross. Allow time for observation and do not begin the turn while the conflict remains unresolved. Check the track's permitted directions, relevant signals and other road users, including pedestrians at the exit.
Denmark's Road Traffic Accident Investigation Board report on cycling collisions at junctions explains how pillars, head restraints and mirror views can conceal a cyclist during a turn. Its recommendations include taking time, reducing speed and changing the viewing angle. The Danish curriculum, sections 7.13.3–7.13.5, covers right-turn observation and yielding to relevant cyclists.
Turn each answer into an observation plan
For each original hypothetical situation above, identify the intended movement, the possible conflict and the missing view. Then explain what would make you wait and what new information would allow a safe decision. Try changing one detail: a different vehicle, a longer delay or a two-way cycle track. Check whether your reasoning still works.
This lesson teaches observation principles, not a universal sequence of national traffic rules. Ireland and Great Britain drive on the left; Denmark drives on the right. Use your country's current guidance and qualified instruction for positioning, signals and priority. These examples are independent study material; instructor review of TheoryTestEU remains pending. Read our editorial policy or report an unclear explanation.