Highway slip testing.
Where Section 41 meets the pavement.

The highway slip claim — and why it's under-documented

Slip claims against highway authorities occupy a strange position in UK personal injury law. Under Section 41 of the Highways Act 1980, the authority has a statutory duty to maintain the highway. Under Section 58 it has a statutory defence where it took such care as was reasonable. But the authority cannot call on that defence if it has no evidence of the actual slip resistance of the surface at the material time.

Most highway inspection regimes focus on potholes, surface defects, kerb damage and signage. Few include pendulum testing as a routine element. Where claims proceed to trial, the absence of pendulum evidence on the claimant's side is as problematic as its absence on the authority's side — but the authority is the one with the statutory duty.

The highway environments we test

Pedestrian crossings

Zebra crossings, signal-controlled crossings, puffin and toucan crossings. The contrasting painted or thermoplastic markings typically have different slip properties from the surrounding carriageway. Worn zebra stripes in particular can drop to PTV 20–25 in wet conditions — creating a specific hazard at the very point a pedestrian is stepping onto the carriageway.

Tactile paving

Yellow tactile paving at crossings is specified for visual and tactile guidance, not primarily for slip resistance. The protruding blisters can have markedly different slip behaviour from the flat surface between them — and the adjacent footway often has a different surface again. Pendulum testing documents each.

Cycle paths and shared-use surfaces

Segregated cycle tracks, shared pedestrian/cycle surfaces, and toucan-crossing pedestrian/cycle zones. Slip resistance for cyclists has a different dimension from pedestrian slip — the latter being the normal BS EN 16165 concern, the former tested where relevant under EN 13036-4 (the highway/road pendulum standard). Both benefit from pendulum measurement on the same apparatus.

Resin-bound and coloured surfaces

Resin-bound pavements are increasingly specified in conservation areas and high-amenity public realm. Coloured thermoplastic surfacing appears at conservation area crossings and cycle-friendly areas. Both have highly variable pendulum performance depending on binder age and aggregate selection.

Pedestrianised streets

Granite setts, porphyry, reconstituted stone, conservation-grade paviors. High-amenity street design materials often perform well when new and deteriorate over 5–10 years with freeze-thaw, polishing under footfall, and weather exposure.

Car parks, yards and service areas

Concrete yard surfaces, tarmac car parks, motorway service station paving. The boundary zone between highway and adopted-forecourt is a frequent claim hotspot.

Bus stops and transport interchange

Bus stop waiting areas, boarding platforms, railway station forecourts and pedestrian transport interchange. High footfall with weather contamination and frequent transition zones.

Who commissions highway pendulum testing

• Highway authorities — county, unitary and metropolitan councils with Section 41 responsibilities.
• Design consultants — establishing a performance baseline for specification writing.
• Contractors — demonstrating compliance at scheme handover.
• Transport operators — Network Rail, Transport for London, bus operators managing passenger-adjacent paving.
• Claimant and defendant solicitors — pre-proceedings evidence gathering.

Highway PTV considerations