Protected intersection

Features of a road protected intersection, as commonly used in the Netherlands

A number of features make this intersection safer. A corner refuge island, a setback crossing of the pedestrians and cyclists, generally between 1.5–7 metres of setback, a forward stop bar, which allows cyclists to stop for a traffic light well ahead of motor traffic who must stop behind the crosswalk. Separate signal staging or at least an advance green for cyclists and pedestrians is used to give cyclists and pedestrians no conflicts or a head start over traffic. The design makes a right turn on red, and sometimes left on red depending on the geometry of the intersection in question, possible in many cases, often without stopping.[5]

Strong ground marking is key to define the cycle lane path and its priority. Wide strips are painted aside the cycle way and 'shark teeth' (triangles with pointy end oriented toward the non priority vehicles) are used to remind priority to the right turning motorists and sometimes also on the motor lane inlet in the intersection.

In addition to ground marking, the cycle lane color play a role to remind cyclist priority, the lane losing its color if the designer decides that the cycle lane shall lose priority (which is uncommon on this type of intersection). In the Netherlands, the cycle way red color is not painted but embedded in asphalt to increase durability and reduce costs.

Also often the cycle lane is slightly raised in the crossing, to again invite motorists to decrease speed.

The protection of the vulnerable cyclists with a protected junction with bicycle traffic lights.

Cyclists ideally have a protected bike lane on the approach to the intersection, separated by a concrete median with splay curbs if possible, and have a protected bike lane width of at least 2 metres if possible (one way). In the Netherlands, most one way cycle paths are at least 2.5 metres wide.[6]

Reduced radius could increase difficulties to turn for larger vehicles (trucks and busses), so in some cases, partly 'climbable' islands have been devised, similarly to what could be found on center island of some small roundabout.

3D view of a protected roundabout, as commonly used in the Netherlands

Protected roundabouts are a variation of protected intersections for lower traffic flow, without the traffic lights.[7]

Alternative dutch roundabout

Alternative design with increased distance from intersection for cycle and pedestrian crossing and motorists having priority over cyclists may be safer and more practical with double direction cycle path.[8]

In The Netherlands, a not for profit organisation working on standardisation and research on traffic, transport and infrastructure, the CROW (dutch),[9] have published since 2006 a design manual for all cycling infrastructure, with an English version of the last edition of 2017.[10]

The concept of Dutch protected intersection got international public attention after an April 2011 blog post ‘State of art bikeway design, or is it ?’ by Mark Wagenbuur [11][12] on David Hembrow blog associated with a video [13] criticising a US junction design published in NACTO design guide, his post trying to explain the Dutch philosophy of pedestrian and cyclist friendly junctions. To emphasize his point, the video schematics were based upon dimensions and schematics of the NACTO publication.

A month later, Mark Wagenbuur published another post trying to clarify the concept and avoid misunderstanding: ‘State of the art bike way design - a further look ’ [14][15] with a new video.[16]

In the USA, Nick Falbo, a member of a US planning firm which was originating the NACTO design, Alta planning+design, published in February 2014 a small web presentation site ‘protectedintersection.com’ [17] of his interpretation of Mark Wagenbuur posts.

In February 2014, David Hembrow published a blog post «The myth of standard Dutch junction» [18]

The same month, Mark Wagenbuur published on his own blog a new clarification post ‘Junction design in the Netherlands’[19] criticising some design he considers being a wrong interpretation of his posts.

Then Alta planning+design published in December 2015 a PDF presentation with a short USA history, schematics and dimensions and some examples of realisations of ‘protected intersections’ in the USA and Canada which may differ from the Dutch practice.[1]

• Cycling infrastructure
• Hook turn