In April 2024, a municipal district in the East of Ireland conducted a review of their road maintenance strategy. Increased levels of traffic and rainfall caused a rise in potholes the previous year, resulting in a threefold spike in vehicle damage claims.
With the cumulative rainfall for 2024 above average by April, the district was aware that the maintenance workload was likely to increase later in the year unless additional pre-emptive maintenance was carried out. They wanted to evaluate all repair methods to see which offered the best value in dealing with the unforeseen workload increase.
The main determining factors they considered were cost, efficiency and carbon output.
Manual repair crews were an option, but the district was hesitant as this would take the crews away from equally important work such as drainage and footpath repairs.
Spray patching was another viable alternative. Having rented a Roadmaster SIP machine during high season in the past, the area engineer was aware of the versatility and efficiency of the machines
Outside of pothole repair, they had used the SIP machine to seal areas of the road that were displaying minor defects and alligator cracking. This was a highly effective and efficient way of maintaining sections of road that were deemed ineligible for the Annual Works Program. They had also found the patcher very effective in sealing and providing texture depth to trench reinstatements and large patch repairs.
Manual Repair vs Spray Patching
Trials were carried out to compare manual repair and Roadmaster SIP machines in terms of safety, repair lifespan, cost and carbon output.
Safety Comparison
Safety is always a concern with manual repair, as the crew members perform the repair manually on the live carriageway, increasing their risk from active traffic. The crew members also operate in close proximity to the three supplementary vehicles in the work train, increasing the risk further.
On the other hand, Roadmasters are managed by a single operator from the safety of the cab, making them a much more secure option.
Equipment and Manpower Comparison
Manual repair required a lot more equipment and manpower than the Roadmasters. This increases the cost per repair and the overall disruption to the road user while the repair is being carried out.
Repair Lifespan Comparison (assumed based on past experience)
Manual Repair                                    Spray Patcher
12 months                                               36 months
From previous experience, Roadmaster repairs tend to last 100% longer than manual repair repairs.
Cost Comparison
Manual Repair                                    Spray Patcher
€734.28/ton                                         €152.73/ton
When the lifespan of the repairs were considered, it was found that velocity patching repairs were 79% less expensive than the manual repair system being used.
Carbon Comparison (over the lifespan of repair)
Manual Repair                                    Spray Patcher
3.19Kg Co2e/M2Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â 0.8 Kg Co2e/M2
Roadmaster repairs resulted in a 75% carbon reduction over the lifespan of the patch.
Full Trial Results Summary
| Cost | |||
| Cost Per Ton Laid | €305.45 | €734.28 | 58% |
| Annualised Average Cost Per Ton | €152.73 | €734.28 | 79% |
| Carbon | |||
| Average Kg Co2e/M2 Over Repair Period | 1.6 | 3.19 | 50% |
| Annualised Average Kg Co2e/M2 Over Repair Period | 0.8 | 3.2 | 75% |
Conclusion
The results show Roadmaster SIP machines to be more cost and carbon-efficient for road repairs. Safety and disruption to traffic is also significantly reduced.