It has been used in Denmark and Sweden since the 1990s. This form of road is of similar profile to wide two-lane, but includes a central crash barrier, and has three lanes, with an overtaking lane on one side or the other, alternating every 2 km. However, due to the deceptive perception of safety given by such roads, future upgrade projects are likely to be 2+1 road where traffic volume suits (a successful pilot installation was used on the N20 near Mallow, County Cork). In the Republic of Ireland, many national primary roads were upgraded in the 1990s and 2000s to wide two-lane road (two-lane road with space for three lanes, in addition to hard shoulders) to allow more space for overtaking (a very common manoeuvre in a country that had little dual carriageway until the early 2000s).
In Australia, drivers can cross a solid centreline to overtake a cyclist.
In the UK and New Zealand, the format of the centerline is not used to regulate overtaking, only to indicate whether crossing of the line is prohibited or permitted. In some jurisdictions, the "overtaking zone" is indicated by a single broken centerline (yellow or white in most countries) if overtaking is allowed in either direction, or paired with a single solid line beside it to indicate there is no overtaking from the solid side. In the UK, guidance for passing and overtaking is given in rules 162-169 of the Highway Code. For example, in New Zealand it's instructed in the Road Code that an overtaking driver must be able to see at least 100 metres (330 ft) of clear road in front of them as they finish the passing manoeuvre). An overtaking vehicle must be able to see clearly ahead of them for the entire overtaking manoeuvre plus a margin of error.
On a single-carriageway/undivided-highway road, the lane used for overtaking is often the same lane that is used by oncoming traffic. Rules of overtaking In English-speaking countries 1.2.1 Nationwide ban on overtaking as road safety measure.