Collisions with Deer on Ireland’s Motorways

AIE Request, Dec 2022

Under the AIE Regs to request any data / records related to deer road traffic accidents for 2020-22

Reported Collisions with Deer on Ireland’s Motorways (2014 to Q3 2020)

Data File, Excel: Deer Only Collisions

Deer Management – Pilot Study

Pilot study to investigate deer collisions on the N77, South of Abbeyleix.

The study will be carried out in a scientific manner and shall develop site specific implementable mitigation measures based on methods that have been shown to be effective.

The lessons learned from this work package are to feed into, and inform, Work Package 3.3q which includes the development of a new suite of documents that will sit within TII Standards Publications to cover all aspects of deer
management relevant to National Roads Schemes.

Abbeyleix Pilot Project


In 2021, TII commenced a deer management pilot project on a 2.5km stretch of the N77 south of Abbeyleix.

The purpose of this pilot project was twofold: firstly, it aimed to examine the causes of deer vehicle collisions along this stretch of road and set out potential mitigation proposals; and, secondly, it was aimed at informing a broader study to look at several case studies nationally and produce a suite of standard documents related to deer management in the context of road safety.

A further follow on study to the pilot study mentioned above is currently being scoped. This proposed study, subject to approval and funding, will involve:

  • an analysis of several ‘hot spots’’, and
  • the development of mitigation proposals in respect of same along with the production of a suite of technical standards documents.

TII holds a very large volume of records across a number of staff members relating to this topic. In response to your request TII has provided a number of records which may address the key areas set out in your request.

Deer Management Templates / Guides

Click to access guide_writing.pdf

Section 42

Risk assessments of Sika deer (Cervus nippon)

ISEIA protocol. Guidelines for environmental impact assessment and list classification for non-native organisms in Belgium.

Click to access ISEIA_protocol.pdf

Risk assessment of Sika deer Cervus nippon in the Netherlands

UK Non-native Species Risk Assessment

Belgium: Risk analysis of the sika deer Cervus nippon (Linnaeus 1758)

Risk assessment for Sika deer (Cervus nippon): risk assessment developed under the “Study on Invasive Alien Species – Development of risk assessments to tackle priority species and enhance prevention”

IAS Workshop

Ireland (risk assessment is understood to be ongoing)

Risk Assessments

Irish risk assessments for other deer are here:


Common misconceptions about risk assessments:

To address a number of common misconceptions about non-native species risk assessments, the following points should be noted:

– Risk assessments consider only the risks posed by a species. They do not consider the practicalities, impacts or other issues relating to the management of the species. They therefore cannot on their own be used to determine what, if any, management response should be undertaken.

– Risk assessments are advisory and therefore are part of the suite of information on which policy decisions are based.

– Completed risk assessments are not final and absolute. They are an assessment based on the evidence available at that time. Substantive new scientific evidence may prompt a re-evaluation of the risks and/or a change of policy.

Deer Management Planning

NPWS are responsible for deer management in Irish national parks

Glenveagh National Park is the only national park with a written deer management plan. The Glenveagh plan was requested by FOI. See below for details

“In Glenveagh National Park, the management of red deer must now be regarded as integral to the process of achieving biodiversity objectives throughout the National Park as a whole. At the current population density, red deer are having no discernible negative impacts on upland Blanket Bog habitats and a negligible impact on woodland regeneration. These conditions can only be maintained if deer density and other ecological indicators are persistently monitored. Management objectives can then be reviewed and modified if deemed necessary. As a keystone species, red deer can have either positive or negative effects on a range of habitats and their dependent species but this is entirely dependent on a range of variables. Many of these effects, particularly those on birds, vertebrates, insects and invertebrates have never been fully scientifically assessed and the loss, damage or benefits to ecosystem function have never been effectively measured. Therefore, if biodiversity and management objectives are to be successfully achieved, there needs to be a sea-change in the way in which deer management is both perceived and implemented within NPWS.”