This is not the first time National Highways has closed a cycle path in a bid to limit exposure to overly high pollution levels. National Highways said at the time that the road will not comply with legal NO2 limits until 2030. According to emails seen by Laker, during the National Highways’ air quality audit, proposals to introduce barriers, clean air zones, and tunnels were dismissed, with the path’s closure the only option considered viable. It continued: “National Highways has a legal duty to consider measures where annual average nitrogen dioxide (NO₂) concentrations exceed the legal limit. That’s a failure of central government primarily but National Highways is not without blame.