ViaEM’s Hazel Road: From Design Intuition to Measurable Carbon Impact

The challenge

Hazel Road: a Thoughtful Starting Point to Turn Early Decisions into Maximum Impact

The Hazel Road scheme was a standard carriageway resurfacing project in Nottinghamshire, designed to receive a 100 mm inlay treatment. The ViaEM engineering team made a thoughtful, conscious effort to use sustainable materials, selecting a specification that applied circular-pavement principles by combining a mechanically robust SMA surface course with a lower-carbon binder layer.

- 40 mm Warm-Mix SMA surface course incorporating 10% RAP, providing a durable, textured surface with reduced mixing temperatures.
- 60 mm Cold Recycled Bound Material (CRBM), utilising the available tar-bound material and foamed bitumen to deliver a structurally efficient, lower-emissions binder layer.

This choice successfully balanced performance, supplier reliability, and local availability. It was a good decision.

But was it the best decision among all possible material scenarios?

Historically, Via East Midlands had to make material choices based on:

- Fragmented material data across standards and spreadsheets
- Limited visibility into the full range of low-carbon material options
- Slow, manual cycles that made exploring alternatives slow and cumbersome
- Siloed knowledge, as each project's learnings didn't systematically inform the next

The consequence was that some high-impact opportunities for carbon and cost savings were difficult to identify early in the process.

"We knew early-phase decisions matter. But we didn't have the data to optimise them," explained Peter Wells, Highway Asset Manager at ViaEM.

The core question the team sought to answer was: what material specification delivers the proper performance while minimising both cost and carbon?

The solution

An Early-Phase Intelligence tested on Hazel Road as Proof-of-Concept

Rather than relying solely on intuition, ViaEM partnered with ORIS to conduct a retrospective analysis: "If we'd had comprehensive material visibility upfront, what scenarios should we have considered?"

The core strategy was digital optioneering: using ORIS to rapidly evaluate viable material specifications against the project's cost and carbon criteria. The team focused on two questions:

1. How much carbon did the material choice we made actually save?
2. What other material scenarios existed that we didn't evaluate?

To answer these, ORIS was used to assess four distinct material and supplier scenarios:

- Conventional HMA Design: Hot-Mix Asphalt for both surface (SMA) and binder (AC) layers, representing a standard baseline.
- High-RAP Warm-Mix Alternative: Surface course with 20% RAP and binder course with 50% RAP, using Warm-Mix Asphalt to reduce mixing temperatures.
- Implemented Design: SMA surface with 10% RAP combined with Foamix CRBM, a Quick Visco-Elastic (QVE) Cold Recycled Bound Material (CRBM).
- Optimised Low-Carbon Designed: SMA with 20% RAP paired with a slow-reacting visco-elastic CRBM, maximising potential carbon reduction.

This systematic approach allowed the team to:

- Test & compare multiple scenarios in minutes, not weeks.
- Clearly compare trade-offs in decision dashboards that tell the story behind the numbers.
- Map transport impacts with high precision to identify where local sourcing could cut emissions.

The outcomes

“We Will Be No Longer Guessing”: from Intuition to Measurable Outcomes

The analysis yielded three critical insights.

26% Carbon Reduction Achieved: Material Choice is the Primary Lever

ViaEM's actual material specification (warm-mix asphalt with RAP + Foamix) delivered 26% carbon reduction compared to conventional hot-mix asphalt with virgin aggregates.

This was a genuine achievement: thoughtful engineering + available data + good supplier relationships = meaningful carbon savings.

But here's the critical insight: this result was based on the material options ViaEM had visibility into. Engineers made the best choice with the information available. The sustainability benefits were real, but the analysis revealed an important point.

A New Alternative Unveiled: A Different Material Scenario Worth Exploring

The ORIS retrospective analysis identified a different material scenario, one that uses alternative cold-recycled bound material technology, that the data suggests might achieve up to 35% carbon reduction compared to the conventional baseline.

Without systematic early-phase material benchmarking, this option didn't surface in their evaluation set. The product is available in the market and has proven performance in comparable contexts, but it requires different supplier qualifications and a more limited track record in this specific application.

This is not a missed opportunity in the sense that “we should have chosen this option.” Instead, it is a realisation: the data revealed a concrete scenario that warrants technical evaluation alongside ViaEM's other constraints: performance requirements, supplier availability, financial implications, and project-specific feasibility.

47% Transport Emissions Difference: Supplier Selection Multiplies Impact

A separate but equally important finding: when ORIS benchmarked ViaEM's selected supplier (Breedon, Mansfield—approximately 25 km from the site) against the next-closest alternative for the same material:

47% lower carbon footprint for transport emissions with the local choice, plus:

- 51% reduction in transportation time
- 41% lower transportation costs

ViaEM selected a nearby supplier for operational reasons, a logical choice. But the data revealed the magnitude: proximity creates compound leverage when combined with brilliant material selection.

What Hazel Road Reveals About Early-Phase Design For Infrastructure Projects

Early-phase analysis turns intuition into data-backed confidence: make these material comparisons before the design is locked, when you still have choices. That's when early-phase insights drive the decisions that matter.

Optimise material selection with data-driven comparisons: systematically evaluate conventional vs. low-carbon alternatives, accounting for cost and carbon footprint trade-offs. Early visibility into feasible options allows engineers to make informed choices before specifications are locked in, maximising both sustainability and cost-efficiency.

Comprehensive material visibility surfaces options you might not discover on your own: leverage a verified database of materials with associated carbon data, filtered by application type and regional availability. Scenarios that might otherwise remain undiscovered are brought into the evaluation process, enabling rigorous, data-backed decision-making.

That's early-phase optioneering. And it starts with reliable data at the design stage.