Study on the economic effects of the 2003 heat wave on transport Alistair Hunt Metroeconomica & University of Bath

2 Structure of talk  Context of study  Role of historical analogues in climate change impacts research  Impacts and costs of Summer 2003 on roads in UK  Lessons for the future

3 Context of study  Initially for UKCIP – Costing case study of 2003 Summer for Cambridgeshire roads – with Chris Capps (Cambs. County Council)  Defra wanted UK total costs of Summer 2003  expanded geographical (and impact) coverage  10 August 2003, record temp - Faversham (Kent) reporting the highest at 38.5 °C.  Fourth warmest summer period on record

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6 Daily maximum temperature: probability of exceedance Central England summer temperature Baseline ( ) 31 o C has 1% chance [I day per summer] 2080s, medium-high emissions 31 o C has 11% chance [11 days per summer] 39 o C has 1% chance

7 Changes in average precipitation - Summer

8 Changes in average soil moisture content (2050s)

9 Summer 2003 impacts on roads  high temperatures - deformations in the surface of roads,  Type of road influences susceptibility to high temperatures, - asphalt and concrete behave in different ways.  Black surfaces melted and led to wheel rutting during summer of Causes aggregate to subside and the road to lose its grip (road-stone polishing).  (Other impacts):  cars with air conditioning had higher fuel use during the period;  vehicles were more susceptible to break-down – particularly from over heating.

10 Summer Cambridgeshire  Fens in Cambridgeshire made up of peat-containing wetland  Subsidence due to the desiccation and shrinkage of the peat deposits  Cambridgeshire County Council spent > £19 million on scheduled highway maintenance schemes.  Large number of additional structural maintenance schemes in need of urgent attention as a result of drought. Cost of schemes = £3.5 million.  Additional £1.1 million spent on emergency repairs of the highway due to cracking and deformation, which without attention would have left the roads in a dangerous condition.

11 Summer 2003 – UK-wide  Assumptions/limitations  Quantify costs associated with road subsidence.  Incidence confined to roads in management of local authorities Assumed to be because A-roads and Motorways built to different construction specification and therefore less vulnerable to subsidence.  Supporting this assumption, no additional funds were requested by UK Highways Agency for subsidence repair work following summer of  No estimates of time loss values and other WTP to avoid damage, e.g. to vehicles, as a result of road subsidence.  use restoration costs to proxy for impact costs

12 Summer 2003 – UK-wide costs  Costs split between local authority and central government:  local authorities have access to emergency running costs cover under 'Bellwin Scheme' in LG and Housing Act 1989 up to 85% of overall costs, <2 Months.  If significant damage > 2 months months - DfT considers contingency funding  DfT policy: contribution to capital costs of reconstruction, though LA to spend > 15% of annual capital road maintenance grant  In this instance a number of counties, including Wiltshire, Surrey, Bedfordshire, Suffolk and Norfolk were not eligible for DfT additional support.

13 UK Regional road subsidence costs – Summer 2003

14 UK County road subsidence cost shares – Summer 2003

15 Costs to all transport modes – Summer 2003 ModeImpacts in summer 2003Valuation RailSpeed restrictions: passenger delay£ 2.2 million (a) Rail buckles: additional maintenance£1.3 million (b) RoadSubsidence£40.6 million (c) UndergroundChanges in demand£0.5 million Health effects< £0.01 million

16 Welfare Costs (Benefits) of Hot Weather Event of Summer 2003 in UK Sector2003 £m Health41 ( ) Energy*80 Agriculture (Arable crops)**88 Transport46.6 Retail+3.2 Water- Tourism38 (23-53) Built Environment124

17 Lessons for the future: Avoiding future damages – examples of adaptation  Reactive: repair regime as now  Proactive: up-grade road surfaces further from current British Standard (revised after hot summer of 1995).  Proactive Tree felling since trees remove moisture from soil and if close to road actually deform the road.

18 Lessons for the future (cont.) Policy  Public bodies need to prepare for greater call on repair funds – if surfaces and road structures likely to remain vulnerable  Funding rules may need to be revisited Research  Since more pressure on funding likely, more attention on justification likely e.g. WTP to avoid time delays, frequency of events etc.