Overtaking

Overtaking or passing is the act of one vehicle going past another slower moving vehicle, travelling in the same direction, on a road. The lane used for overtaking another vehicle is often a passing lane farther from the road shoulder, which is to the left in places that drive on the right and to the right in places that drive on the left.
On a single-carriageway/undivided-highway road, the lane used for overtaking is often the same lane that is used by oncoming traffic. An overtaking vehicle must be able to see clearly ahead of them for the entire overtaking manoeuvre plus a margin of error. 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. In the UK, guidance for passing and overtaking is given in rules 162-169 of the Highway Code.
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 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 Australia, drivers can cross a solid centerline to overtake a cyclist.
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). 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). 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. It has been used in Denmark and Sweden since the 1990s.
On a dual-carriageway/divided-carriageway highway/motorway or arterial road, any lane can be an overtaking lane though in many places (including Germany) undertaking (overtaking on the side furthest from the road center line) is prohibited. Lanes are normally separated by broken lines (usually white) but may be a single solid white to indicate lane-changing is allowed but discouraged. Double lines indicate that lane-changing (for example to overtake) is prohibited, such as in tunnels or sometimes for HOV lanes and HOT lanes.
Overtaking in an HOV or HOT lane is usually illegal for cars that do not meet the HOV/HOT criteria, except when directed by the police.
A few places also use the one-broken/one-solid marking at slip roads/entrance ramps, to indicate to highway drivers that the new lane merges and does not continue, so they do not attempt to overtake in a lane that ends shortly. This is also used at other points where lanes merge.
The no-overtaking-sign looks a lot the same in most European countries, but its legal description differs between countries. Depending on the text of law, in some countries in Europe the no-overtaking-sign bans overtaking only for vehicles that have three or more wheels, effectively granting motorcycle drivers the freedom to overtake cars even past the no-overtaking-sign, where the same sign rules out overtaking for all types of vehicles in neighboring countries. In other jurisdictions, like the Netherlands, overtaking vehicles that have only 2 wheels is not forbidden, despite the no-overtaking sign. The law text 'overtaking vehicles on more than two wheels' allows for overtaking bicycles, of which there are many on Dutch roads.
Many jurisdictions mandate a safe overtaking distance when passing pedestrians, cyclists, persons on horseback, motorcyclists, or those on motorized scooters. For instance, Germany and the United Kingdom both prescribe a horizontal overtaking distance of at least 1.5 metres (5 ft).
The Netherlands has ruled out overtaking on 95% of their single carriageway primary road network. Statistics from before 1990 showed that many fatal accidents in the Netherlands were due to unsafe overtaking actions, where the speed of oncoming traffic was underestimated. During the 1990s a new road design was introduced, called 'Duurzaam Veilig (Verkeer)', or "Sustainable (Road) Safety". The philosophy behind the new road design was that the road had to protect its users against death or injury, by creating a design that has to eliminate common mistakes that often lead to accidents. This vision moves the responsibility for road safety away from the road users towards road designers. The 'Duurzaam Veilig'-road design created 3 categories of roads: roads meant for local access, regional distributor roads (called 'gebiedsontsluitingswegen', or GOW) and national through roads, each with their own type of lines on the edge of the road, so road users would be able to recognize what type of road they were on and behave accordingly. By strictly separating slow moving local traffic from faster moving through traffic, the 'Duurzaam Veilig'-project aimed at making roads safer through their design.
One of the new features on regional distributor roads (GOW) was a wide double centre line, often without interruption, designed to create more lateral space between two opposite directions of traffic and to stop people from overtaking. Designers of the wide double centre line wanted to create some room for human error, so that vehicles swerving towards the centre of the road would no longer immediately lead to fatal accidents. The idea behind the solid centre line was the thought that overtaking cars have to move into lanes with oncoming traffic, which was considered unsafe even on perfectly flat and straight stretches of road with proper visibility. People in favour of the 'Duurzaam Veilig'-project point out that it has succeeded in creating more safety, as the number of fatal accidents has gone down quite dramatically as 'Duurzaam Veilig' road design was rolled out across the Netherlands.
In countries bounded by Vienna Convention on Road Traffic, article 11 states that:
Local governments may introduce variations to the Convention.
Overtaking on the inside or undertaking refers to the practice of overtaking a slower vehicle on a road using the lane that is curb side of the vehicle being passed; that is to say, a lane to the left of the vehicle in countries where driving is on the left, or a lane to the right of the vehicle in countries where driving is on the right. The practice of passing on the inside, therefore, usually only occurs on a motorway or other road where there is more than one lane in the same direction or when the width of the roads makes this possible (although there may be exceptions in the cases of contraflow bus lanes).
Many countries consider overtaking on the inside dangerous and therefore designate it a driving offence; however, most countries make the distinction between involuntary undertaking (passing centre side vehicles in heavy traffic) as opposed to the deliberate attempt to pass a slower moving vehicle for one's own benefit.
Below are some common examples of traffic signs prohibiting overtaking.
In racing, the rules allow overtaking from either side. Generally, the sides are classified as inside and outside overtaking, depending on the position of the overtaking car at the next curve since start of overtaking. The defending car usually blocks inside overtaking, because outside overtaking is riskier than inside overtaking.