Port Erin 20mph

Summary

The requester asked for details on the methodology, software, and external consultants used to define Port Erin's proposed 20mph speed limits. The Department of Infrastructure responded that no automated processes or external consultants were used, relying instead on manual officer assessments, and stated that no supporting technical documentation is held.

Key Facts

• No automated or computer-based processes were used to select or delineate the 20mph areas.
• Departmental officers used relevant criteria and site assessments to develop the proposal.
• No external consultants, contractors, or off-island advisers were engaged for the project.
• The officer assessment was undertaken throughout 2024.
• The authority does not hold any technical reports, correspondence, or GIS output files regarding the boundary derivation.

Data Disclosed

• 2024
• 20mph
• 5067364
• 2025-11-06
• 2025-12-04

Original Request

I would be grateful if you could provide the following information in relation to the Port Erin Existing and Proposed Speed Limit Plan currently under consultation. 1. Methodology and Tools * Was any automated or computer-based process (for example, GIS modelling, density or buffer analysis, or software-generated zone mapping) used to select or delineate the proposed 20 mph areas? * If so, please identify: a. The software or model used; b. The input datasets or criteria applied (e.g., residential density thresholds, school buffers, etc.); c. The date the analysis was undertaken and by whom. 2. Human Review * Was any on-site or manual assessment undertaken by Department officers to validate or amend the computer-generated boundaries? * Please supply any notes, internal emails, or reports describing how the proposed limits were verified on the ground. 3. External / Off-Island Consultants * Were any consultants, contractors, or external advisers (including off-island firms) engaged in preparing, analysing, or mapping the Port Erin speed-limit proposals? * If yes, please provide: a. The name of each consultant or company; b. The scope of their involvement; c. The dates of any site visits or inspections carried out in Port Erin; and d. The cost or contract value (if available). 4. Supporting Documentation * Please provide copies of any technical reports, correspondence, or GIS output files showing how the proposed 20 mph boundaries were derived.

Data Tables (1)

Full Response Text

Department of Infrastructure Sea Terminal Building, Douglas, Isle of Man, IM1 2RF

Contact: FOI Response Team Telephone: (01624) 686785 Email: dpo-doi@gov.im

Our ref: 5067364 2 December 2025

Dear ###

We write further to your request, received 6 November 2025, which states:

"I would be grateful if you could provide the following information in relation to the Port Erin Existing and Proposed Speed Limit Plan currently under consultation.

1. Methodology and Tools

2. Was any automated or computer-based process (for example, GIS modelling, density or buffer analysis, or software-generated zone mapping) used to select or delineate the proposed 20 mph areas?

3. If so, please identify:

a. The software or model used;

b. The input datasets or criteria applied (e.g., residential density thresholds, school buffers, etc.);

c. The date the analysis was undertaken and by whom.

1. Human Review

2. Was any on-site or manual assessment undertaken by Department officers to validate or amend the computer-generated boundaries?

3. Please supply any notes, internal emails, or reports describing how the proposed limits were verified on the ground.

4. External / Off-Island Consultants

5. Were any consultants, contractors, or external advisers (including off-island firms) engaged in preparing, analysing, or mapping the Port Erin speed-limit proposals?

6. If yes, please provide: a. The name of each consultant or company;

b. The scope of their involvement;

c. The dates of any site visits or inspections carried out in Port Erin; and

d. The cost or contract value (if available).

1. Supporting Documentation

2. Please provide copies of any technical reports, correspondence, or GIS output files showing how the proposed 20 mph boundaries were derived."

While our aim is to provide information whenever possible, in this instance the public authority does not hold or cannot, after taking reasonable steps to do so, find some of the information that you have requested.

I have detailed below the information that is held:

1. Methodology and Tools

There were no automated or computer-based processes used to select or delineate 20mph residential roads. Departmental officers used relevant criteria and site assessment to develop the proposal. The criteria is available to view on the government's 20mph consultation website, via the following link
https://20mph.gov.im/southern/

a) Not applicable b) Not applicable; refer to aforementioned criteria. c) The officer assessment was undertaken throughout 2024.

1. Human Review

a) There were no computer/software generated boundaries. All site and office-based assessment was undertaken by officers. b) Refer to above.

1. External/Off-Island Consultants

No external consultants were used.

1. Supporting Documentation

No information held.

While this response is in relation to Port Erin, the same application has been consistently applied across all locations on the Island.

Please quote the reference number 5067364 in any future communications.

Your right to request a review

If you are unhappy with this response to your freedom of information request, you may ask us to carry out an internal review of the response, by completing a complaint form and submitting it electronically or by delivery/post.

An electronic version of our complaint form can be found by going to our website at https://services.gov.im/freedom-of-information/Review . If you would like a paper version of our complaint form to be sent to you by post, please contact me and I will be happy to arrange for this. Your review request should explain why you are dissatisfied with this response, and should be made as soon as practicable. We will respond as soon as the review has been concluded.

If you are not satisfied with the result of the review, you then have the right to appeal to the Information Commissioner for a decision on; 1. Whether we have responded to your request for information in accordance with Part 2 of the Freedom of Information Act 2015; or 2. Whether we are justified in refusing to give you the information requested.
In response to an application for review, the Information Commissioner may, at any time, attempt to resolve a matter by negotiation, conciliation, mediation or another form of alternative dispute resolution and will have regard to any outcome of this in making any subsequent decision. More detailed information on your right to a review can be found on the Information Commissioner’s website at www.inforights.im. Should you have any queries concerning this letter, please do not hesitate to contact me. Further information about freedom of information requests can be found at www.gov.im/foi.

I will now close your request as of this date.