Ireland - Traffic and Transport Assessment

TTRSA's experienced transport planning specialists work as a team to deliver high quality and cost effective Traffic and Transport Assessments, Traffic Impact Assessments, and Transport Statements anywhere within the country. The main elements of Traffic and Transport Assessments (TTA) are outlined below.

Traffic and Transport Assessment Guidelines

TTA guidelines for Ireland, which superseded the former Traffic and Transport Assessment (TIA) guidelines, are maintained and published by the National Roads Authority (NRA).

When is a TTA likely to be required?

Whilst the latest NRA TTA guidelines published in September 2007, suggest thresholds for the production of a TTA, many local authorities have their own threshold values. Examples of threshold values include:

  • when the predicted traffic generated to and from the development exceeds 10% of the traffic flow on the adjoining road, or 5% in congested or sensitive locations;
  • residential developments in excess of 50-100 dwellings in urban areas;
  • retail or leisure developments in excess of 1000sqm gross floor area (GFA);
  • office, educational or hospital developments in excess of 2500sqm GFA;
  • industrial developments in excess of 5000sqm GFA;
  • distribution or warehousing developments in excess of 10000sqm GFA;
  • stadia with a capacity of over 1500 people;
  • community facilities (including churches) in excess of 1000sqm GFA;
  • when a development is predicted to generate more than 100 trips in the peak hours;when 100 parking spaces are provided; or,
  • when the predicted traffic generated by the development exceeds 10% of the turning movements at a junction with a national road, or 5% in congested or sensitive locations.

TTAs are also likely to be required when a development is not consistent with the relevant Development Plans and Local Area Plans, may have an incremental impact, may generate particular patterns of traffic or heavy goods traffic that may be a concern.

How is the content of a TTA determined?

A fundamental element of the production of any TTA is effective scoping with the local planning and highway authorities. Effective scoping limits the content of the TTA, often producing significant cost savings for the developer, and also reduces the likelihood of a local authority either requesting Further Information on the traffic and transport aspects of a development, or refusing a proposed development because of concerns related to traffic impact.

Those commissioning a consultant to produce a TTA should ensure that the consultant intends to scope the work with the relevant local authority and that the format of the TTA report will be consistent with that set out with the NRA guidelines.

What if my development is near or adjacent to a National Road?

Those planning developments near or adjacent to National Roads should also consider the NRA policy statement on "Development Management and Access to National Roads" published in May 2006. In circumstances where local planning authorities have given permission to developments near to the new inter-urban routes, the NRA has been seen to object successfully to An Bord Pleanála.

How can TTRSA help me?

TTRSA have considerable experience in assessing the impact of developments and working with developers and local highway authorities to development appropriate and cost effective solutions to problems. With the addition of our traffic count and road safety audit services, we can normally address all of your traffic and transport related development needs in-house.

We are always happy to informally discuss your situation and requirements, or provide a cost effective quotation. We can be contacted on 01 5143748, or by email at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .