The design is distinct in that the lights controlling the pedestrians are on the same side of the road as the pedestrian user, rather than on the opposite side as in the older pelican crossing it replaces.
They have two sensors on top of the traffic lights (PCD pedestrian crossing detector and PKD pedestrian kerb detector). These sensors detect if pedestrians are crossing slowly and can hold the red traffic light longer if needed. If a pedestrian presses the button but then walks off, the PKD will cancel the request making the lights more efficient.
Unlike the older pelican crossing designs, where the pedestrian signal lights are mounted on the opposite side of the road, the puffin crossing has them mounted at the near road side, set diagonally to the road edge. This allows the pedestrian to monitor passing traffic while waiting for the signal to cross. A second reason for the design is that having the lights closer to the user assists visually impaired people who could have difficulty viewing the signal from across the carriageway.
Some push-button units (the lower box in the image) are also fitted with a tactile knob under the unit which rotates when the user may cross. This feature is to assist visually impaired people who struggle to see the light change.
After a request to cross (by button press), a kerb side detector monitors the pedestrian's presence at the crossing. Should the pedestrian cross prematurely, walk away from the crossing, or wait outside the detection area, the pedestrian's request to cross could be automatically cancelled. This is so traffic is not halted unnecessarily. An on-crossing detector ensures that the signal for vehicles remains red until pedestrians have finished crossing (within practical limits). Unlike the pelican crossing, there is no transitional "flashing" phase.
The pedestrian phase will start at the moment all three of these conditions are fulfilled:
- the pedestrian push button has been pressed since the end of the last pedestrian phase
- the "Maximum Traffic Green Timer" has expired
- the detectors indicate that a pedestrian is still waiting to cross
The "Maximum Traffic Green Timer" is started either when the pedestrian push button is pressed or when the traffic signals first turn green after the previous pedestrian phase. The latter arrangement is termed the "pre-timed Maximum Facility".
Concerns have been expressed that Puffin crossings may be less safe than Pelican crossings due the nearside indicator not being visible while crossing, and being at a different focal length, reducing traffic awareness. However, a 2005 study commissioned by the DfT found that Puffins were safer than Pelican crossings with fewer pedestrian accidents and fewer involving cars, despite confusing pedestrians. Transport for London decided to stop installing Puffins in 2014, as they prefer the far side indicators. Birmingham Council also dislike the low level indicators at busy city centre crossings.
- "Foreword, Puffin Good Practice Guide" (PDF). Department for Transport. 2006. Archived from the original (pdf) on 3 January 2009.
- "Rule 199". The Highway Code. Department for Transport. Retrieved 18 June 2012.
- "Inquiry launched into 'Puffin' crossings amid safety fears". Road Safety GB. 3 May 2012. Archived from the original on 12 February 2015. Retrieved 12 February 2015.
- "Puffin crossings - a blunder? - Page 64 - SABRE". sabre-roads.org.uk. Retrieved 13 December 2016.
- The History of British Roadsigns, United Kingdom Department for Transport, 2nd Edition, 1999
- Puffin Good Practice Guide, UK Department of Transport, 2006
- Puffin Good Practice Guide Video, UK Department of Transport, 2006
- "The Installation of Puffin Pedestrian Crossings" (PDF). UK Department of Transport. January 2002. Archived from the original (PDF) on 8 August 2007.
- "Puffin Pedestrian Crossing" (PDF). UK Department of Transport. February 2001. Archived from the original (PDF) on 8 August 2007.