What following distance should I leave on a Northern Ireland motorway?

On a Northern Ireland motorway, leave at least a two-second gap in good dry conditions and increase it substantially in poor weather or visibility.

This is a specifically Northern Ireland question because the applicable road rules, DfI/DVA processes and Northern Ireland Highway Code are the relevant reference point. The Highway Code’s general following-distance rule applies at motorway speed, where stopping distances are long. At 70 mph, two seconds represents a large physical distance; in wet conditions the gap should be at least doubled.

For this exact issue — “What following distance should I leave on a Northern Ireland motorway?” — the Northern Ireland motorway rule has to be applied with high-speed safety in mind. Check the live signs, lane status and whether you are dealing with normal driving, congestion or a genuine emergency. Hard shoulders, emergency areas and motorway lanes are controlled spaces, so actions that would be ordinary on a local road can be prohibited or extremely dangerous here.

Use a fixed roadside point to count the gap and increase it further in ice, fog, heavy spray or when towing. If signs, licence categories, vehicle plates or official instructions conflict with something remembered from an older guide, follow the current official information and the live road signs.

Before publishing this answer, the key factual point in “What following distance should I leave on a Northern Ireland motorway?” was checked against current Northern Ireland official guidance. That matters because road rules, licence entitlements and enforcement details can differ from Great Britain and can change over time; the sources attached below are the ones to re-check if the rule is updated.