Past studies about cyclist conspicuity


What works?

  • Fluorescent/reflective clothing such as a ‘high-vis’ jacket is not very good at increasing a cyclists' visibility/conspicuity to drivers, in particular after dark [Wood et al 2010, Rogé et al 2019].

  • There is some evidence that bio-marking (reflectors on the wrists and ankles) greatly improve conspicuity [Costa et al 2017, Edewaard et al 2017, 2020, Wood et al 2010, 2012]

  • Problem: cyclists tend to overestimate their conspicuity to drivers [Wood et al 2013] which means they are less likely to appreciate the need to take necessary precautions. Instead, bicycles (and cycling clothing) should be manufactured with conspicuity-enhancing features already built-in [Fylan et al 2020].

  • Studies which have investigated the effect of 'high vis' jackets on cyclist conspicuity using RTC data have reached opposing conclusions. While one study found that 'high vis' jackets are not very good at increasing cyclist visibility [Miller et al 2017] another found that cyclists are protected against RTCs when wearing one [Lahrmann et al 2018]. This may be a result of differences in method: Lahrmann et al used self-reporting of RTCs from participants who took part in a non-blinded randomised control study, and therefore their responses may be influenced by response bias. Both studies included RTCs in daylight as well as after dark.

Limitations of studies investigating bio-marking:

  1. Cyclists are always viewed from behind. No studies have tested the degree to which bio-marking (reflective strips on pedals) benefits a front-facing cyclist.

  2. Bio-marking is always a reflective strip: no studies have consider active devices, i.e. lights rather than reflectors, which should offer greater contrast against the background, do not require illumination from the vehicle headlights, and are likely to increase detection distance.

  3. While eye tracking has been used to investigate conspicuity aids for pedestrians [Wood et al 2017] this method has not been applied to cyclists.

Detection tasks

Analysis of RTC data

User perceptions


  • Costa M, Bonetti L, Bellelli M, Lantieri C, Vignali V and Simone A (2017). Reflective tape applied to bicycle frame and conspicuity enhancement at night. Human Factors, 59(3), 485-500.

  • Edewaard D E, Fekety D K, Szubski E C and Tyrrell R A (2020). Highlighting bicyclist biological motion enhances their conspicuity in daylight. Accident Analysis & Prevention, 142, 105575.

  • Edewaard D E, Fekety D K, Szubski E C, Tyrrell R A and Rosopa P J (2017). The conspicuity benefits of dynamic and static bicycle taillights at night. In Proceedings of the Human Factors and Ergonomics Society Annual Meeting (Vol. 61, No. 1, pp. 1567-1568). Sage CA: Los Angeles, CA: SAGE Publications.

  • Fylan F, King M, Brough D, Black A A, King N, Bentley L A and Wood J M (2020). Increasing conspicuity on night-time roads: Perspectives from cyclists and runners. Transportation research part F: traffic psychology and behaviour, 68, 161-170.

  • Koo H S and Huang X. (2015). Visibility aid cycling clothing: flashing light-emitting diode (FLED) configurations. International Journal of Clothing Science and Technology.

  • Lahrmann H, Madsen T K O, Olesen A V, Madsen J C O and Hels T. (2018). The effect of a yellow bicycle jacket on cyclist accidents. Safety science, 108, 209-217.

  • Miller P D, Kendrick D, Coupland C and Coffey F. (2017). Use of conspicuity aids by cyclists and risk of crashes involving other road users: population based case-control study. Journal of Transport & Health, 7, 64-74.

  • Rogé J, Laurent S, Ndiaye D, Aillerie I and Vienne F. (2019). Does a yellow jacket enhance cyclists’ sensory conspicuity for car drivers during daylight hours in an urban environment?. Safety Science, 119, 385-391.

  • Rogé J, Ndiaye D, Aillerie I, Aillerie S, Navarro J and Vienne F. (2017). Mechanisms underlying cognitive conspicuity in the detection of cyclists by car drivers. Accident Analysis & Prevention, 104, 88-95.

  • Twisk D A M and Reurings M. (2013). An epidemiological study of the risk of cycling in the dark: The role of visual perception, conspicuity and alcohol use. Accident Analysis & Prevention, 60, 134-140.

  • Washington S, Haworth N and Schramm A (2012). Relationships between self-reported bicycling injuries and perceived risk of cyclists in Queensland, Australia. Transportation research record, 2314(1), 57-65.

  • Wood JM, Tyrrell RA, Lacherez P, Black AA. Night-time pedestrian conspicuity: effects of clothing on drivers eye movements. Ophthalmic & Physiological Optics 2017; 37: 184-190.

  • Wood J M, Tyrrell R A, Marszalek R, Lacherez P and Carberry T (2013). Bicyclists overestimate their own night-time conspicuity and underestimate the benefits of retroreflective markers on the moveable joints. Accident Analysis & Prevention, 55, 48-53.

  • Wood J M, Tyrrell R A, Marszalek R, Lacherez P, Carberry T and Chu B S (2012). Using reflective clothing to enhance the conspicuity of bicyclists at night. Accident Analysis & Prevention, 45, 726-730.

  • Wood J, Tyrrell R, Marszalek R, Lacherez P, Carberry T, Chu B and King M.(2010). Cyclist visibility at night: perceptions of visibility do not necessarily match reality. Journal of the Australasian College of Road Safety, 21(3), 56-60.