[[File:13-06-27-rotterdam-by-RalfR-27.jpg|thumb|The protection of the vulnerable cyclists with a protected junction with bicycle traffic lights.]]
In terms of optimal spacing between the path and motorist lanes, it is generally practice to use 2–5 meters at signalised crossings and one car length >5m5 m at unsignalised intersections. Providing more buffer space allows vehicles, particularly those turning out of smaller roads, to queue in the waiting area. On the other hand, larger buffers could place the cyclist at a less optimal viewing point from the mainline, and delay the signal operation due to longer distances necessitating slightly longer bicycle signal yellow and all red clearance intervals. The exact optimal distance has been the subject of several studies.<ref>{{Cite journal|last=Schepers|first=Paul|date=2011|title=Road factors and bicycle–motor vehicle crashes at unsignalised priority intersections|url=https://doi.org/10.1016/j.aap.2010.11.005|journal=Accident Analysis and Prevention|volume=43|issue=3|pages=853–861|doi=10.1016/j.aap.2010.11.005|pmid=21376876|via=}}</ref><ref>{{Cite journal|last1=Richter|first1=Thomas|last2=Sachs|first2=Janina|date=2017-01-01|title=Turning accidents between cars and trucks and cyclists driving straight ahead|journal=Transportation Research Procedia|series=World Conference on Transport Research - WCTR 2016 Shanghai. 10–15 July 2016|language=en|volume=25|pages=1946–1954|doi=10.1016/j.trpro.2017.05.219|issn=2352-1465|doi-access=free}}</ref>
