Stripped of the formal wording, Rule 229 comes down to one idea: rule 229 (Icy and snowy weather (rules 228 to 231)) Before you set off - you MUST be able to see, so clear all snow and ice from all your windows - you MUST ensure that lights are clean and number pl… Because it is written with “MUST” or “MUST NOT”, it carries the force of law, ignore it and you are committing an offence, not simply driving badly.
It belongs to the driving in adverse weather conditions part of the Code, the habits a confident, considerate driver builds until they are automatic. The aim is not to memorise the sentence word for word, but to understand the hazard it protects you from, so you apply it without having to think when it counts.
If you are learning, treat this rule as one piece of a connected set rather than an isolated fact. The related rules below sit in the same section and reinforce each other, reading them together is how the driving in adverse weather conditions part of the Code starts to feel like common sense rather than a list to revise.
Because this is a legal rule, the consequences of ignoring it reach beyond the test: a “MUST” or “MUST NOT” breach can mean a fixed penalty, points on your licence, or in serious cases prosecution. Either way, the safe move is to build the habit early, while a driving instructor can correct it, rather than relearning it under test pressure. That is exactly what the practice routes and coaching in the DriveRoutes app are designed to help with, turning the rules below into the way you naturally drive.