TMH-18 data preparation and validation

Start with the exchange definition

TMH-18 defines how road-asset data are exchanged. The edition and file family establish field meanings and layout. A readable file can still use the wrong identifiers, network version or units. Select the agreed definition before choosing a validation template.

Keep the untouched export, the receiving authority’s instructions and the relevant network definition together. Review field order, delimiter, encoding and missing values in the saved text. A renamed extension does not convert a legacy layout.

Review the checks and the remaining questions

TMH18 Validator checks a file against the selected template. File acceptance and a clean result do not establish that every clause of the manual was checked or that field measurements are correct. Read errors, warnings and skipped checks before moving the file through review.

Use the guides below in sequence: confirm the edition, prepare the file, resolve network and distance problems, then preserve the findings and handover evidence. Geometry components and field-assessment evidence need their own agreed review where they fall outside the selected checks.

Sources and scope

• COTO TMH-18: Road Asset Data Electronic Exchange FormatsCommittee Draft 5.0, February 2016. Cover; §1.6, Table 5; §1.7, Table 6.
• COTO TMH-18: record conventionsCommittee Draft 5.0, February 2016. §1.1, Table 1: encoding, delimiters, empty fields and headers.
• COTO TMH-18: network measurement and historyCommittee Draft 5.0, February 2016. §§2.2–2.2.2; §5 introductory rules; §5.1, Table 12.

The cited sources describe their own requirements. Practical checklists and examples do not replace the receiving authority’s adopted profile. Platform review and certification are described in the product documentation.