Methods

• Observed Recorded by FR8 from a public feed, such as a traffic count.
• Published Stated by a publisher or carrier, copied as printed.
• Estimated Computed by a named FR8 method below. An estimate is always labelled as an estimate.

Corridor HGV norm from per-interval rates: for each week, HGV counted divided by the 15-minute intervals filled at qualifying site-days (at least 68 of 96 intervals), scaled to every corridor site for a full week. The norm is the mean of that figure for the same ISO week in the previous 3 years, using weeks with at least 70% of intervals filled and at least 3 sites qualifying (5 or more qualifying days). The deviation compares the week's figure with the norm and is given only when the week itself has at least 70% of intervals filled and at least 3 qualifying sites. A silent site lowers coverage, not the figure. Deviation is an estimate.

• HGV flow counts vehicles over 11.6 m at the corridor's count sites (WebTRIS length band 1160+ cm), both directions.
• A site-day qualifies when at least 68 of its 96 15-minute intervals are filled. A site qualifies for a week when 5 or more of its days qualify.
• The rate is the HGVs counted divided by the intervals filled, over qualifying site-days. FR8 scales it to every corridor site for a full week (sites x 7 x 96 intervals), so a site that sends nothing lowers coverage, not the figure.
• The norm is the mean of that scaled figure for the same ISO week in the previous 3 years, using only weeks with at least 70% of intervals filled and at least 3 qualifying sites.
• The deviation is the week's scaled figure against the norm, in per cent. It is given only when the week itself has at least 70% of intervals filled and at least 3 qualifying sites.
• Limit: when a site that is busier or quieter than the corridor average sends nothing, the scaled figure shifts with the mix of reporting sites. Coverage is shown beside every weekly figure for this reason.

National Highways WebTRIS publishes counts with a lag of about 6 months. In October 2026, filled rows run to mid-April 2026. FR8 labels road data "Latest week available" with its date, as a dated record of a past week.

Next fuel surcharge step: the latest published fuel index applied to the carrier's published band table. The result is an estimate until the carrier publishes.

• FR8 takes the carrier's latest published band table and the latest public point of the fuel index it names.
• The band that holds the index value gives the estimated next step.
• Timing follows the carrier's printed lag rule where it publishes one, otherwise the next published period.

Status is a set of category tiles. It has no combined score and no ranking.

• Normal: no change on the previous period.
• Notable: any change on the previous period, or any Freight Anatomy change in the last 7 days.
• Elevated: a corridor's deviation from norm in the latest week available is -10% or lower, or a surcharge increase above 10% in the last 7 days.
• Stale: the latest figure is older than its freshness window: 21 days for fuel, 8 weeks for road. Because of the WebTRIS lag, the road tile is usually Stale. Stale is never shown as Normal.
• Precedence: Elevated, then Stale, then Notable, then Normal. An Elevated road tile still names the latest week available and its date.

Every source is fetched with the user agent N84-FR8/1.0. Before each carrier page is fetched, FR8 reads that site's robots.txt; a disallowed path is not fetched. The raw bytes are kept privately before any parsing, so a parsing fault never loses a day of history. Raw copies and carrier documents are never published. A site that refuses automated requests is not worked around.

Each history states the date of the first successful capture of its source. The record grows from that date with every capture. For road corridors, the earlier weeks shown come from the WebTRIS archive.