S30093 Development of new Lead Safety Indicators validation and verification of selected recommended indicators

National Highways Strategic Safety Team in the Road Safety Division want to procure

through the SPaTS 3 framework a Direct Award to WSP for the continued development

of Lead Safety Indicators (LSIs) project (T0631) through a re validating and verification

stage. In the National Highways 2024-25 annual delivery plan we committed to

developing a set of LSIs. ORR is following progress on this. It is understood that DfT is

expecting at least one lead safety indicator (in addition to the existing iRAP metric) to be

added to our formal organisational performance metrics during RIS3.

National Highways' key performance indicator for road user safety on the Strategic

Road Network (SRN) (KPI1) is a lagging indicator, focused on impacts. A lagging

indicator is reactive in nature and measures the performance of an aspiration or

outcome after an event has occurred. They don't tell us how we're performing at

preventing casualties and reducing future collision severity. There is also a time lag of

knowing the results of a lagging indicator, for example, 2024 stats 19 data was

published on 25 September 2025. Although measurable and quantifiable, lagging

indicators alone are not enough, and they don't provide insight into factors that lead to

those outcomes without in-depth analysis.

LSIs are proactive, preventive measures (or metrics) used to shed light on the level of

safety performance achieved in a system through monitoring and intervention. A lead

indicator attempts to measure control and preventative activities that precede or

indicate likely failures. They are designed to understand what is happening earlier in the

process in order to prevent and control lagging indicators. Therefore, to improve road

safety on the SRN (and reduce KSIs), there is a need to identify, monitor and positively

influence LSIs. Our iRAP performance indicator (percentage of traffic using iRAP 3 star

or above rated roads, and flow-weighted decimal star rating) is a lead indicator, but as

we are only able to conduct a full survey once every 5 years, we need additional

measures that can provide earlier and more frequent indication of safety performance

and therefore any need for change in approach or additional intervention within the 5

year period.