Use infrastructure to reduce vehicle collision risk along roads

How is the evidence assessed?
  • Effectiveness
    not assessed
  • Certainty
    not assessed
  • Harms
    not assessed

Study locations

Key messages

  • One study evaluated the effects on butterflies and moths of using infrastructure to reduce vehicle collision risk along roads. This study was in the USA.




  • Behaviour change (1 study): One controlled study in the USA reported that “altitude guide” netting, and poles topped with bright colours or flowers (attractive features), did not alter the behaviour of Oregon silverspot around roads.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

  1. A controlled study in 2012 on a disused road in Oregon, USA (Zielin et al. 2016) reported that “altitude guide” netting, and poles topped with bright colours or flowers, did not alter the behaviour of Oregon silverspot Speyeria zerene hippolyta butterflies. Results were not tested for statistical significance. Of 54 Oregon silverspots which encountered a net erected next to a road, only 10 flew over it, compared to 29 which flew around it, two which walked through it, and 13 which turned around. Of the 39 butterflies which flew over or around the net, 10 subsequently landed on the road. When the net was not present, 35 out of 60 butterflies flew between the net poles, nine turned around, and only four butterflies landed on the road. In a second experiment, of 41 Oregon silverspot that flew within one metre of poles topped with bright colours or flowers (attractive features), none ascended to the top. In 2012, a decommissioned road was divided into ten 8 × 7 m2 sections, spanning the 4-m-wide road and 2 m either side. Six trials, consisting of four 15-minute observation periods, were conducted on different sections. For two periods/trial, a 3-m-tall, 2-cm mesh net was stretched between two pairs of poles (7 m apart) on each side of the road, and for the other two periods the nets were absent. No further details provided. On 25 August and 1 September 2012, seven 1-m-high poles topped with attractive features: a bright colour (red: 3 poles, yellow: 2 poles) or flowers (2 poles), were observed for a total of 90 minutes. No further details provided.

    Study and other actions tested
Please cite as:

Bladon A.J., Bladon, E. K., Smith R.K. & Sutherland W.J. (2023) Butterfly and Moth Conservation: Global Evidence for the Effects of Interventions for butterflies and moths. Conservation Evidence Series Synopsis. University of Cambridge, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

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Butterfly and Moth Conservation

This Action forms part of the Action Synopsis:

Butterfly and Moth Conservation
Butterfly and Moth Conservation

Butterfly and Moth Conservation - Published 2023

Butterfly and Moth Synopsis

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