“We`ve received a lot of very positive feedback about the difference roundabouts make to the driving experience for Northland residents,” said Andrew Thackwray, National Director of Infrastructure Delivery at Waka Kotahi. Lane location and right-of-way at roundaboutHigh-speed pointSigns at roundabouts (straight, turn left, turn right)Do not signal if you are at risk of losing controlMulti-lane roundabouts “A big problem in roundabouts is uncertainty – drivers don`t know what to do and what other drivers are doing.” There are some legal considerations regarding certain specific types of roundabouts designed for cyclists. These include aspects not yet included in the regulations, such as the signage on roundabouts C required to indicate that heavy vehicles must cross lanes, the use of harrows and markings indicating a transition from a cycle path to a central position. The following links provide more information on specific ways to cycle at roundabouts: However, accident rates for injuries to cyclists at roundabouts are generally higher than for other types of intersections. In addition, the impact speed of the safety system threshold for pedestrians, cyclists and motorcyclists is 30 km/h, which is easily exceeded at most roundabouts. The three roundabouts already in use are located in places that are very popular with locals and visitors to the area – all three are on the Twin Coast Discovery Route, Northland`s main tourist artery. Austroads Guide to Road Design – part 4B: Roundabouts (external link) provides advice on three categories of observation for drivers approaching roundabouts. It should be noted that visual criterion 1 (view of the roundabout entrance from the approaching road) and criterion 2 (view of the vicinity of the approaching traffic line) are considered mandatory because of their impact on safety. However, there are optional indications on the visibility of criterion 3. This criterion measures a driver`s view of other vehicles further away as they approach the roundabout. Compliance with this criterion allows the approaching driver to search for other vehicles from a distance and assess whether he needs to brake to yield the right of way at the roundabout or whether he can cross unhindered. Although better visibility is often considered safer, there is good evidence that in practice at intersections and roundabouts, it is safer to restrict visibility until the driver is closer to the roundabout.
Despite these considerations, European research and best practice show that roundabouts can be designed in a way that is compatible with the principles of safe systems, making them safer and more attractive to pedestrians, cyclists and motorcyclists. Instead of marking bike lanes inside roundabouts, bike lanes should end at roundabout entrances at least 30 metres from the boundaries so that cyclists can switch to general lanes or an alternative off-road route. This arrangement is presented in MOTSAM Part 2, Section 3.18 [PDF, 6 MB]. Signal on the left before entering the roundabout. Signal on the left before leaving the roundabout. Forcing cyclists to move to the left of vehicles inside the roundabout increases the likelihood of conflict between cyclists in circulation and vehicles entering (or, to a lesser extent, exiting), as the route planned by cyclists is not necessarily obvious to motorists and motorists are more likely to look for other cars than cyclists. This is especially important for multi-lane roundabouts where “seen but don`t” accidents can be common. Two-lane roundabouts can be made safer for confident cyclists, but are never an attractive facility for all types of cyclists. Even for multi-lane roundabouts, it may not be necessary to provide multiple lanes at all entrances or exits and it may be possible to reduce the number of bypass lanes on certain sections of the roundabout.
As a general rule, a one-lane exit should be preceded by a single bypass. The Austroads research (“Assessment of the effectiveness of on-road bicycle lanes at roundpicks in Australia and New Zealand”) identified 25 km/h as the desirable entry speed for cyclists to occupy the lane safely, 30 km/h being the maximum allowed by this definition and also being the safe speed threshold for pedestrians and cyclists. If you avoid more than half of a roundabout: If you are driving straight through a roundabout: Therefore, no other cycling facilities (e.g., forward stop lines, forward stop boxes, or hook turn boxes) should be reported at roundabouts. The only exception is marked roundabouts, where advanced storage facilities (boxes or lines) for cyclists can be installed. Visibility between roundabouts is an important design parameter. As the expected boarding speed for an approach increases, so does the required visibility. However, visibility also affects the input speed. The approach speed can be reduced by limiting the distance between the entrance to the roundabout where the view of conflicting traffic is reached. The roundabouts were designed with a safe systems approach in mind, as Waka Kotahi is committed to Vision Zero, which aims for a New Zealand where no one is killed or seriously injured on our roads. Signs, road markings, and rules for crossing roundabouts generally work the same way for everyone on the road.
Be wary of cyclists who may have difficulty holding a turn signal in a roundabout and who are exempt from the signalling requirement. Three new roundabouts were opened in Northland before Christmas – in Waipapa on State Highway 10, in Kawakawa at the intersection of SH1 and SH11, and at Puketona Junction at the intersection of SH10 and SH11. A fourth roundabout is under construction on SH1 in Kaitaia and will be operational by the end of the month. Research and experience show that limiting the distance from the boundary line where visibility is reached reduces the approach speed of the vehicle. If an incoming driver is looking for conflicting traffic near the border, a traveling cyclist or motorcyclist is more likely to be seen. This reduced visibility and approach speeds have been shown to reduce accidents for all urban roundabouts. In a study on the development of accident prediction models reported in “Roundabout crash prediction models” (NZ Transport Agency research report 386), Turner et al. (2009) showed that visibility measured 10 metres from the boundary line was strongly correlated with approach speed. Most roundabouts that have more than one lane in each direction are marked with lanes and arrows to facilitate entry and exit from the roundabout.