The report “Motorcyclists and Barriers” (PPR2051, version 1.0) presents an updated assessment of the risk that roadside barriers pose to motorcyclists on the UK Strategic Road Network (SRN). It builds on a 2014 study carried out by TRL for Highways England, now National Highways, and incorporates the most recent casualty data available up to 2018. The collaboration involved TRL as the research contractor and National Highways as the commissioning body, with the project funded through the National Highways research programme. The original work was completed in 2014, and the update extends the data analysis to 2018 while retaining the literature review and testing sections from the earlier report.

The technical findings confirm that motorcycle‑to‑barrier incidents are rare but disproportionately severe. Between 2014 and 2018 there were 174 recorded motorcycle‑to‑barrier crashes on the SRN, representing only 0.2 % of all SRN casualties. However, 76 % of these incidents resulted in killed or seriously injured (KSI) riders, compared with 16 % for non‑motorcycle barrier impacts. When adjusted for exposure, motorcycles suffer 2.33 fatal collisions per billion vehicle kilometres, roughly 33 times the rate for cars (0.07 per billion km). These statistics underscore the heightened vulnerability of motorcyclists to barrier impacts.

The report’s cluster analysis identified that the majority of incidents occur at junctions, particularly grade‑separated junctions, and that slip roads account for almost a quarter of all motorcycle‑to‑barrier crashes. Notably, the number of incidents on slip roads with a curve radius under 100 m is comparable to those on straight link road sections, suggesting that installing shorter lengths of Motorcyclist Protection Systems (MPS) on curved slip roads could achieve benefits similar to longer installations on straight roads, which are more costly and difficult to implement.

The literature review and market survey reveal that current MPS are only effective in about half of the cases because they are designed primarily for sliding impacts, whereas many motorcycle crashes involve a rider striking a post while upright. The testing standard TS 1317‑8, which specifies impact performance requirements for MPS, includes acceptance criteria such as a Head Injury Criterion (HIC36) of ≤ 10 000, neck shear force ≤ 3 300 N, and neck bending moment ≤ 134 Nm. The report notes that many existing MPS meet these limits when the rider’s head is aimed at a post, but performance degrades when the impact angle or point of contact differs.

Based on these findings, the report recommends a risk‑reduction policy that prioritises the installation of MPS at high‑risk locations identified through the cluster analysis, particularly on slip roads and tight curves within grade‑separated junctions. It also suggests that National Highways consider the cost‑effectiveness of shorter MPS sections on curved slip roads, as well as the potential for design improvements that address upright impacts. The recommendations aim to reduce the high severity of motorcycle‑to‑barrier incidents while acknowledging the practical constraints of barrier retrofitting across the SRN.