Request ID: FOI-0302-2425 Date published: 10 May 2024
You asked
Will it be possible please to let me know how TfL ensures that road bridges on the TLRN are compliant to relevant standards for both HA and HB loading, the frequency for inspections and testing and methodology used.
As of 31/03/2024 what number and percentage of stock were compliant, and what is the target Bridge Condition Index (BCI) for each road bridge and the target BCI average of the stock?
We answered
TfL Ref: FOI-0302-2425
Thank you for your request received by Transport for London (TfL) on 25th April 2024 asking for information about road bridges on the Transport for London Road Network (TLRN). Your request has been considered in accordance with the requirements of the Freedom of Information Act and our information access policy.
Specifically you asked:
“Will it be possible please to let me know how TfL ensures that road bridges on the TLRN are compliant to relevant standards for both HA and HB loading, the frequency for inspections and testing and methodology used.
As of 31/03/2024 what number and percentage of stock were compliant, and what is the target Bridge Condition Index (BCI) for each road bridge and the target BCI average of the stock?”
I can confirm that we hold the information you require.
In answer to the first set of questions, TfL carries out load assessments for TLRN structures in accordance with national standards (currently CS454 Assessment of highway bridges and structures) and they are periodically reviewed to ensure that load capacity information is kept up to date. The interval between Inspections are risk-based (complying with best practice recommendations) and are typically 2-3 years for General Inspections with Principal Inspections executed typically every 4-8 years. TfL follows the national standard on Inspections (CS450 Inspection of highway structures), supplemented by a TfL procedure on condition inspections to capture TfL specific requirements for inspections. Testing is determined and undertaken on a case by case basis in accordance with relevant standards and best practice.
In answer to the question for data from 31/03/2024, assuming that by ‘compliance’ you mean those which meet relevant standards with respect to HA loading (i.e. vehicles that comply with the Road Vehicles Construction and Use Regulations 1986 (C&U loading) and generally accepted to be 40t vehicles), the numbers and percentages for those structures designated as sub-standard in accordance with CS470 ‘Management of sub-standard highway structures’ are as follows:
12 structures ( 3.2% of the total stock)
TfL does not define a target Bridge Condition Indicator for individual structures, but monitor and manage them on a risk basis to ensure they remain safe and fit for purpose. Similarly TfL does not specify a target BCI average for the stock.
If this is not the information you are looking for please do not hesitate to contact me.
Please see the attached information sheet for details of your right to appeal as well as information on copyright and what to do if you would like to re-use any of the information we have disclosed.
Yours sincerely,
David Wells FOI Case Officer FOI Case Management Team General Counsel Transport for London
