Alan McMurray Network Maintenance Manager Department for Infrastructure – Roads Western Division Presentation on Winter Service to Derry City & Strabane District Council 1
Winter Service A battle against the elements! 2
Why Do We Salt Roads ? DFI Roads has no legal obligation to salt roads, however, on about 70 nights each year, road surface temperatures can drop below zero and if moisture is present, a frost can occur. On these nights, DFI Roads carries out precautionary salting at the most effective times to try and prevent ice from forming therefore facilitating the free and safe movement of traffic. Without the Winter Service programme, the network slows and can become impassable. In these instances, there is a significant cost to the economy. 3
Roads (NI) Order 1993: The Department shall take such actions as it considers reasonable to prevent snow and ice interfering with the safe passage of persons and vehicles using the road’ DFI only has a power and not a duty to remove snow and ice 4
Winter Service Policy DFI Roads utilises the well established principle of targeting the limited resources available on the busier main through routes. The policy also makes provision for unscheduled and emergency requests. Utilising this Policy, DFI Roads focuses its winter service resources on the 28% of the network that carries 80% of vehicle km travelled. Salt boxes /Grit piles Around 4800 salt bins and almost 50,000 grit piles. Secondary gritting, as resources permit including: Funerals , Emergency/Medical Services and Animal Welfare. 5
Roads on the Salting Schedule The following routes are included in precautionary salting schedules: Motorways and Trunk Roads. Main Routes – through routes carrying more than 1,500 vehicles per day. Other Busy Routes with special difficulties – (i.e.) through routes carrying - between 1,000 and 1,500 vehicles per day where factors give rise to special difficulty for example: - a) severity, frequency and extent of gradient, frequency of bends, height above sea level Links to small settlements containing 100 dwellings or more. Where alternative routes are already treated simply passing the traffic volume minima does not automatically result in a road being added to the schedule All other routes are normally not salted . (Buses classed as number of vehicles per seat e.g. 50 seater bus is 50 vehicles) 6
Roads not on the gritting network? Subject to certain criteria being met salt bins / grit piles may be provided for the public to use on a self help basis. Salt Bins To qualify for consideration the following factors must apply : - (a) Gradient equal to or greater than 5% / 1:20. (b) No reasonable alternative route available. A points scoring system is in operation to assess need The points scoring system takes into account gradient, availability of alternative routes, geometry, number of residential properties served, community welfare such as schools / residential care facilities and commercial usage. A score of 50 or more is required for qualification. Salt bins shall not generally be provided within 100m of an existing bin 7 7
Grit Piles • Piles of grit or a mixture of grit and salt may be placed in rural locations subject to certain criteria being met • A points scoring system is in place which takes into consideration Gradient Bus route Historical usage Availability of alternative route A score of two or more is required for a grit pile to be provided • There is no restriction on the number of grit piles that can be provided 8 8
So How Big is the Task? DFI Roads salted network is extensive and covers in excess of 7000 kilometres. This is equivalent to the distance from Belfast to Moscow and back. Our target is to complete the salting of this network within 4 hours of any given scheduled start time. Our aim is achieving this target on at least 95% of scheduled actions throughout the winter. 9
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Staff Winter Service is a massive logistical Exercise and requires; Approximately 320 Drivers. 125 Supervisors. 30 Duty Controllers (Decision Makers). Snow clearance contracts, which utilise external resources of farmers, and contractors. 11
Plant No of Gritters Area Depot No. Routes allocated to depot @ present East Airport Road 11 13 21 Depots South Armagh 6 7 West Arvalee 7 8 East Balloo 6 8 107 Routes North Ballykeel 5 6 North Ballymoney 5 6 132 Gritters West Ballyvadden 0 1 South Carn 4 5 South Corbet 4 5 13 Snow Blowers North Larne 4 5 North Limavady 5 6 West Magherafelt 5 7 West Moygashel 6 7 South Newry 5 6 North Northbrook 4 6 North Rathmore 4 5 South Seaforde 7 8 West Silverhill 6 7 East Sprucefield 6 7 West Strabane 3 4 North Woodburn 4 5 Total 107 132 12
Salt DFI Roads preparations for the next winter start immediately following the end of each winter season. Salt Barns, which are strategically located across Northern Ireland are filled to capacity prior to the start of each winter season. The Salt Barns hold around 70,000 tonnes. Additional Salt Resilience Stock totalling over 10,000 tonnes is also held The current Salt Contract (2015-2020)provides for the supply of a further 15,000 tonnes per month from October to April. 13
How we decide when to salt? We obtain daily forecast information for the Met Office which is updated throughout each 24 hour period At any time there are 6 Duty Controllers on duty across NI Duty Controllers are experienced personnel with suitable knowledge and training They know how the weather affects the function of roads They effectively use different sources of information to assess risk in a situation They interpret and make best use of weather forecasting information They make informed decisions regarding the need to salt, quantity of salt to use and timing of actions 14
Dealing With Snow The winter’s worst problems normally occur during heavy and prolonged snowfall, and this is when there is a higher risk of disruption. Clearing snow is much more difficult than dealing with frost, because of the large volume of frozen material. During Heavy snowfall, all efforts are directed to clearing snow from motorways and the trunk roads, before moving to other main roads and the busiest urban link roads. The operation continues until all roads are cleared, but this may take some time even when all resources are deployed. Arrangements are also in place to enlist the help of Contractors (including farmers) to clear blocked roads (Snow Clearance contracts) 15
Snow Plan Maximum effort is concentrated on the more heavily trafficked traffic routes first; i.e. clearing snow from level 1 must be given priority before moving onto levels 2, 3, and 4. Level 1 : trunk roads and motorways only (17% of the schedule). Level 2 : 50% of the salted schedule to pick up the more important roads. Level 3 : 100% of the salted schedule. Level 4 : Roads outside the salted schedule. Additional plant available Assistance from ‘normal’ Department Contractors Assistance from Farmers / other contractors 16
Communications A Winter Service Page is added to Traffic Watch DFI Roads’s public facing Web portal. Social Media messages via Twitter Traffic news emails 17
What Does it Cost ? Approximately 60,000 tonnes of salt is used in an average winter season. (20 year average) This increased to 117,000 tonnes last winter 2017/18. This year by comparison has seen about 40,000 tonnes used. Each action costs an average £80,000 which equates to almost £6million for an average season. £9.7 million for last winter 2017/18 In severe conditions winter service can be a continuous, round the clock operation lasting for several days which is very costly both in terms of funding but also staff resource 18
Why don't we salt more roads ? The Department believes its current criteria provides the most efficient winter service model, balancing the highest volumes at proportionate cost. It has been estimated that to increase traffic capture by a further 10% would require doubling the length of the salted network which in turn would result in approximately twice the cost. 19
Derry City and Strabane District Council Winter Service Total road length – c.2365 km / 1470 miles Total treated length – c. 537 km / 334 miles % of treated network – 22.7% Salt boxes – 425 Grit piles - 5336 2 depots – Strabane & Woodburn 7 routes – 3 Strabane / 4 Woodburn Special arrangements for treatment of Foyle Bridge and Craigavon Bridge which are treated using potassium acetate rather than salt. 20
Derry City and Strabane District Council Winter Service cont’d Routes to rural schools Treated on mornings of ice and snow Shortest distance from school to closest part of remaining scheduled network 8 schools in Derry City and Strabane District Council These schools experienced extended / multiple periods of closure in recent years 21
Derry City and Strabane District Council Winter Service cont’d Schedule of rural schools 2018 / 19 22
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