Report to the Highways and Transport Panel

HERTFORDSHIRE COUNTY COUNCIL

REPORT ON THE DEVELOPMENT OF A COUNTYWIDE FOOTWAY STRATEGY

Report to the Highways and Transport Panel

22 September 2005

Author: Chris Allen-SmithTel: 01707 356573

Purpose of report

To inform Panel Members of progress to date on preparing a countywide footway strategy.
To examine whole life costs for various footway surface types, taking into account the ongoing maintenance and insurance claim costs.
To propose a policy to replace most costly surface types and so reduce whole-life costs.

2.Background

2.1 The Footway Network

2.1.1The countywide network consists of 5134km of footways.Each section of footway is placed in a hierarchical system prioritised from 1 to 5. These are listed below with their percentage of the whole network:

1. / High Traffic (4%) / Mainly town centres
2. / Medium Traffic (10%) / Busy urban footways leading from housing estates to town and city centres, transport interchanges, frequently used public amenities. Main streets in villages.
3. / Low Traffic (High Risk) (2%) / Housing estates with high incidence of defects due to age of footway, extensive utility trenches or vandalism. Lengths where there is significant high numbers of vulnerable users, e.g. outside old peoples homes
4. / Low Traffic (Urban) (79%) / Housing estates and other urban footways
5. / Low Traffic (Rural) (5%) / Little used rural footways.

2.2Footway Surface Types

2.2.1The main surface types and their percentage of the whole network are listed below.

Bituminous (78%) [Bitmac/tarmac and other ‘black’ surfaces]
Concrete flag (16%) [Standard paving slabs and newer, smaller types]
Block Paving (3%) [Brick sized concrete blocks, often coloured]
Other (3%) [Includes special or enhanced surfaces ]

2.2.2Some of the main causes for the deterioration of the existing footway network can be attributed to utility openings, vehicle overrun, tree roots, weathering and fair wear and tear. The effects of these can vary depending upon the surface type. For example, bituminous surfaces become brittle and break down over a period of time due to the effects of weathering, more so than would a concrete flagged footway. Conversely, a concrete flagged footway is more likely to result in trip hazards due to the effects of vehicle overrun or tree roots, and is more difficult to reinstate properly following utility works.

3. Analysis of Lifecycle costs, ongoing maintenance and insurance claim costs

3.1Different Types of Costs Incurred

3.1.1Whole life costs for a particular surface type comprise of several elements. There will be the initial construction costs which could be followed by regular planned maintenance to prolong the serviceable life. For example, this could include slurry sealing a bituminous surface to extend the life and restore the surface. At the end of its serviceable life the cycle begins again with the renewal/replacement of the footway. During the lifecycle there are also regular ongoing costs required to maintain the footway in a safe and serviceable condition. These costs will include reactive maintenance, such as fixing trips as they occur, and insurance claim costs and will tend to increase as a footway approaches the end of its life.

3.2Construction and Planned Maintenance Costs

3.2.1Lifecycle costs for various surface types and maintenance scenarios are shown in Appendix 1. This shows that the cheapest is a bituminous surface treated with a slurry seal or similar on a regular basis costing an average of £1.13 per m2 per year. A concrete flagged footway is the most expensive - nearly twice as muchat £2.23 per m2 per year.

3.2.2Each lifecycle includes a construction/reconstruction cost since footways will periodically need full or partial rebuilding to restore them to optimum condition although the frequency of such reconstructions can be significantly reduced with a well-planned maintenance regime.

3.2.3The diagram below illustrates the concept of the lifecycle of a footway and demonstrates how, in some circumstances, a series of inexpensive surface treatments, applied at the correct time, can be used to maintain the condition and prolong the life of a footway cheaply and effectively.

3.3 Ongoing Reactive Maintenance Costs

3.3.1The regular ongoing costs of maintaining a footway can be divided into three groups:

CAT 1 – Category 1 costs (works of a reactive nature required to put right an unsafe condition, for example, filling potholes or replacing broken/rocking slabs).
CAT 2 – Category 2 costs (minor maintenance works, for example, relaying a section of uneven paving slabs, or resurfacing a small area of bituminous footway)
Insurance Claims – Costs associated with compensation payments for personal injury and damage to property.

3.3.2In the period from 06/01/03 to 25/05/05 a total of £3.7million was spent on CAT 1 repairs across all footway surface types. This equates to an average annual cost of £0.15/m2 /year.

3.3.3In the period from 27/03/04 to 19/05/05 a total of £1.1million was spent on CAT 2 repairs across all footways. This equates to an average annual cost of £0.11/ m2/year.

3.3.4In the period 01/10/02 to 31/05/05 a total of £1.4million was spent/set aside for settling compensation claims relating to defects on the footways. This equates to an average annual cost of £0.05/m2/year.

3.3.5The overall ongoing costs per square metre per year for each surface type are shown in Figure 1. Bituminous footways which make up the majority of the network cost £0.26/m2 per year compared with £0.59/m2 per year for a concrete flagged footway. A breakdown of the costs across each hierarchy can be seen in Appendix 2.

Ongoing Maintenance - Average cost per m2/year

3.4 Overall Lifecycle costs

3.4.1Overall lifecycle figures are obtained by combining all the costs together for a particular surface type. This shows that a bituminous footway on average will cost £1.39/ m2 per year to compared £2.82/ m2 per year for a concrete flagged footway.

4.Comparison of Options for Footway Surfaces

4.1This analysis concentrates on the two most common types of footway surface – concrete slabs and bitmac – as these comprise the vast majority of the network and are consequently where the greatest impact can be made.

4.2A comparison of the lifecycle costs presented in Section 3 shows that bituminous footways are less expensive to build and maintain than a concrete flagged footway, generally have a longer service life between major repairs, attract fewer ‘Category 1’ defects and fewer insurance claims.

4.3From the analysis presented in the various Appendices, it will be seen that the cost of converting a paving slab footway to a bituminous footway is slightly higher than the cost of lifting and relaying the slabs to renew the footway surface. However, this does depend on how many of the slabs are broken and need to be replaced – in some cases relaying in bitmac will be cheaper than relaying the slabs. However, this higher initial cost is more than offset over time by the longer life and lower ongoing maintenance costs. In the past the higher initial cost might have made this option less attractive however, when considering the options as part of a life-cycle cost (a key element of the Asset Management approach to highway maintenance championed by Hertfordshire) we can see the whole-life benefits.

4.4Analysis of the figures suggests that if concrete flagged footways were replaced with bituminous material then a cost saving could be achieved within 5 years. Refer to Appendix 3 for details.

4.5 Bitmac and other bituminous footways also offer a number of other advantages over paving slabs besides the lower whole-life costs:

4.5.1Health & Safety:New guidance on manual handling means that the large, heavy concrete slabs now pose an identified health & safety risk to workers moving and laying them. Under the Construction (Design & Management) Regulations HCC, as the client for the works, has a duty to consider the safety and well-being of workers not just during construction but during subsequent maintenance operations. For this reason, identified risks should be eliminated where practical.

4.5.2Improving Access: Quite aside from reducing the risks to workers, removing paving slab footways helps to reduce the risk to pedestrians, especially the elderly and wheelchair/pushchair users, who tend to find the sharp trips that are created when slab footways become uneven especially difficult to negotiate.

4.5.3 Durability: Although the theoretical life of a concrete slab is almost unlimited, in the modern environment vehicle over-running, stats trenches and tree roots are major factors in the deterioration of footways. Bituminous surfaces tend to be more forgiving in such situations compared with slabs which are more prone to breaking and presenting trip hazards. This is reflected in the higher whole-life cost of slabs.

4.5.4Visual Amenity: The main advantage offeredby slabs is that, at least when in good condition, they are often considered a more attractive surface than bitmac. This is an important factor in the street scene, especially in town-centre areas, and it is proposed that suitable surfaces should be maintained in town-centre shopping streets and similar prestige areas.

5. Proposals

5.1Given the cost savings that could be achieved and other advantages of bituminous surfaces, it is proposed to introduce a Policy to the effect that, when a concrete flagged footway is due to be renewed then it would be with a bituminous surface. The Policy would also require that any new footways would be built with bituminous materials. There would be exceptions to this, such as when the location is within a main shopping centre. A proposed footway Policy wording is shown in Appendix 4.

Issues for the panel to consider

6.1 The Panel is asked to support the introduction of the Footway Policy as shown in Appendix 4.

7.Appendices:

Appendix 1:Lifecycle Costs

Appendix 2:Costs associated with CAT1/CAT2 repairs and insurance claim costs

Appendix 3: Analysis of potential cost savings

Appendix 4: Proposed Footway Policy

Appendix 1: / Lifecycle / costs
Treatment / Year
1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11 / 12 / 13 / 14 / 15 / 16 / 17 / 18 / 19 / 20 / 21 / 22 / 23 / 24 / 25
Bitumen / £24.85 / £24.85
Bitumen + slurry seal / £24.85 / £6.00 / £6.00 / £6.00
Bitumen + microasphalt / £24.85 / £12.67 / £12.67
Concrete slab footway / £29.05 / £29.05
Slab footway converted to Bitumen* / £36.08* / £12.67 / £12.67
Treatment / Year
26 / 27 / 28 / 29 / 30 / 31 / 32 / 33 / 34 / 35 / 36 / 37 / 38 / 39 / 40 / 41 / 42 / 43 / 44 / 45 / 46 / 47 / 48 / 49 / 50
Bitumen / £24.85
Bitumen + slurry seal / £6.00 / £6.00 / £6.00
Bitumen + microasphalt / £12.67 / £12.67
Concrete slab footway* / £29.05 / £29.05
Slab footway converted to Bitumen / £12.67 / £12.67

*The cost of relaying a slab footway assumes that a portion of the slabs are suitable for reuse. Where this is not the case, the cost of this option will be higher.

**The cost to convert a slab footway to a bituminous surface includes a significant allowance for reconstructing the foundation layers of the footway. In practice this is not always necessary and so this cost is a conservative estimate.

Treatment / Adjustment to 50 yr life / Cost over 50 years / Cost per m2/yr
Bitumen / -£5.52 / £49.70 / £0.99
Bitumen + slurry seal / -£4.50 / £42.85 / £0.86
Bitumen + microasphalt / -£10.56 / £50.19 / £1.00
Concrete slab footway* / -£4.47 / £58.10 / £1.16
Slab footway converted to Bitumen / -£10.56 / £61.42 / £1.23
Notes: The 'Adjustment' is the amount of life remaining at the end of the fifty-year period, this is deducted for the total costs to give the cost of a fifty-year life-cycle so that all treatments can be compared on a similar basis.
Appendix 2: Costs associated with Cat 1/Cat 2 repairs and Insurance Claims
HCC Hierarchy / Surface Type / Area of footway (m2) / CAT 1 Repairs (£) / CAT 1 Repairs £/m2/year / CAT 2 Repairs (£) / CAT 2 Repairs £/m2/year / Insurance Claims (£) / Insurance Claims £/m2/year / Total £/m2/year
Bitmac / 367587 / 268924.03 / £0.307 / 36845 / £0.100 / 60246 / £0.061 / £0.469
1 / Concrete Slab / 131232 / 163394.37 / £0.523 / 13761 / £0.105 / 127188 / £0.363 / £0.991
(High) / Blocks / 63962 / 50686.81 / £0.333 / 1849 / £0.029 / 16274 / £0.095 / £0.457
Other / 21197 / 25605.69 / £0.508 / 0 / £0.000 / 2478 / £0.044 / £0.551
Bitmac / 843029 / 332773.19 / £0.166 / 72748 / £0.086 / 50194 / £0.022 / £0.274
2 / Concrete Slab / 148716 / 65677.51 / £0.186 / 27170 / £0.183 / 105967 / £0.267 / £0.635
(Medium) / Blocks / 24682 / 14529.55 / £0.247 / 3650 / £0.148 / 13559 / £0.206 / £0.601
Other / 10628 / 6786.74 / £0.268 / 0 / £0.000 / 2064 / £0.073 / £0.341
Bitmac / 191249 / 84460.31 / £0.186 / 11391 / £0.060 / 13479 / £0.026 / £0.272
3 / Concrete Slab / 19965 / 9970.42 / £0.210 / 4254 / £0.213 / 28456 / £0.534 / £0.957
(Lo - Hi risk) / Blocks / 3091 / 658.7 / £0.090 / 572 / £0.185 / 3641 / £0.441 / £0.716
Other / 2738 / 170.5 / £0.026 / 0 / £0.000 / 554 / £0.076 / £0.102
Bitmac / 6097422 / 1823820.7 / £0.126 / 645147 / £0.106 / 284879 / £0.017 / £0.249
4 / Concrete Slab / 1277610 / 507889.91 / £0.167 / 240948 / £0.189 / 601416 / £0.176 / £0.532
(Lo - Urban) / Blocks / 207471 / 64302.57 / £0.130 / 32367 / £0.156 / 76952 / £0.139 / £0.425
Other / 257104 / 98001.25 / £0.160 / 0 / £0.000 / 11716 / £0.017 / £0.177
Bitmac / 390601 / 55611.19 / £0.060 / 19483 / £0.050 / 9331 / £0.009 / £0.119
5 / Concrete Slab / 6632 / 1365.28 / £0.086 / 7277 / £1.097 / 19699 / £1.112 / £2.296
(Lo - Rural) / Blocks / 1454 / 487.56 / £0.141 / 977 / £0.672 / 2521 / £0.649 / £1.462
Other / 23768 / 1133.97 / £0.020 / 0 / £0.000 / 384 / £0.006 / £0.026
Hierarchy and surface type not recorded / - / - / 119295.04 / - / - / - / - / - / -
Totals / 10090138 / 3695545.29 / 1118439 / 1430998
Average cost m2/year/across all hierarchies
Surface Type / CAT1 / CAT 2 / Insurance claims / Total
Bitmac / £0.137 / £0.100 / £0.020 / £0.256
Concrete Flagged / £0.198 / £0.185 / £0.209 / £0.592
Blocks / £0.183 / £0.131 / £0.141 / £0.454
Other / £0.175 / £0.000 / £0.020 / £0.196
Notes:
Cat 1 costs based on the period 6/01/03 to 25/05/05 (870 days/2.38 years)
Cat 2 costs based on estimated annual spend by district and distributed across by hierarchy as per the HERMIS data for the period 27/3/04 to 19/5/05.
Insurance claims from the period 1/10/02 to 31/05/05 (973 days/2.67 years) and are based on actual costs plus amounts set aside for claims not yet settled

Appendix 3: Analysis of Potential Cost Savings

Countywide area of concrete flagged footways is 1,584,155m2

The total area of concrete flagged footways in ‘High’ category is 131,232m2 which equates to approximately 8%.

Assume that concrete flagged footways in ‘High’ category areas will not be affected by the proposed footway policy to replace them.

Therefore, potentially at least 92% (1,452,923 m2 ) of concrete flagged footways could be converted to bitumen.

From the lifecycle costings, the cost to convert to bitumen is £36.08/m2

The total cost to convert would be £36.08 x 1452923 = £52,421,462.

The ongoing cost savings per year would be the difference in concrete flagged costs minus bitumen costs, ie £0.592-£0.256 = £0.336/m2 /year. (from table in Appendix 2).

The lifecycle cost savings per year between concrete flagged and bitumen are £2.23 -£1.13 = £1.10/m2 /year.

Therefore the total cost savings of bitumen over concrete flagged is £1.10 + £0.336 = £1.44/m2 /year.

Assuming that all the concrete flagged footways that could be were converted to bitumen then the cost saving would be £1.44 x 1,452,923 = £2,092,209 per year.

Assuming an initial cost of £52,421,462 to convert it would take 25 years to recover these costs. However, assuming that these flagged footways would otherwise be reinstated with like for like at a cost of £29.05. The additional cost to convert to bitumen over and above this is £36.08-£29.05 = £7.03/m2 /year.

Therefore the additional costs over what would otherwise be spent are £7.03 x 1,452,923 = £10,214,049. This divided by the cost savings of £2,092,209 per year gives a figure of just under 5 years in which costs could be recovered.

Appendix 4: Proposed Footway Policy

1The options for the replacement/renewal of various footway surfaces within specific area types are detailed below:

Type A - Town Centre – Main shopping street

i)If the existing surface is already bituminous then replacement/renewal shall be with a bituminous material.*

ii)If the existing surface is of pre-cast concrete paving slabs then replacement/renewal shall remain as slabs or change to another appropriate form of surface treatment such as modular or block paving.*

iii)If the existing surface is modular, block or already enhanced surface then replacement/renewal shall be with a similar standard of material so far as is practicable, although the precise nature of the finish may need to be varied.*

* In Type A streets it may be considered appropriate to enhance the existing surface if a 3rd party is willing to contribute the additional costs involved. However the choice of material should fit the County Council’s long term maintenance needs in terms of durability and sourcing replacement materials.

Type B - Non Town Centre and all other areas including local shopping precincts, residential, commercial and rural areas.

i)If the existing surface is already bituminous then replacement/renewal shall be with a bituminous material.

ii)If the existing surface is a non-bituminous surface then replacement shall be with a bituminous material.*

* Exceptionally, at the discretion of the local District Manager a Type B footway with an existing enhanced surface, such as yorkstone paving may be maintained to that standard rather than being replaced with a bituminous material.

Refer to Table 1

2.With the exception of Type A, footways in new developments to be adopted and maintained at public expense shall be constructed in bituminous materials. The same standards shall be applied to improvement or enhancement schemes promoted on the public highway by HCC or partner organisations.

3.When renewing/replacing all surface types of footways, and where not already present, consideration shall be given to the provision of dropped kerbs and tactile paving in line with current guidance where necessary.

Footway Surface Type

Existing surface material / Type A
(Main shopping streets of a town centre) / Type B
(All others areas not covered by type A, including, local shopping precincts, residential, commercial and rural areas)
Bituminous / Bituminous.* / Bituminous.
Precast concrete slabs / A range of options for finished surface can be considered including pre-cast concrete slabs, blocks, bitumen or other appropriate surface.* / Bituminous.
Modular paving/blocks / Existing surface can be maintained at a similar standard so far as is practicable although the precise nature of the finish may need to be varied.* / Bituminous.
Enhanced surface (eg yorkstone paving) / Existing surface can be maintained at a similar standard so far as is practicable although the precise nature of the finish may need to be varied.* / At the discretion of the local District Manager the existing surface can be maintained at a similar standard so far as is practicable, although the precise nature of the finish may need to be varied.

Table 1 - Acceptable replacement/renewal surface types for footways based on area type and existing surface material.