The study hypothesised that there would be a change in levels of active travel (walking and cycling) as a result of the intervention of free bus fares for young people (see Chapter 4) which may lead to a change in physical activity. This section examines whether or not we can estimate the benefits from a change in physical activity as a result of the scheme.
Methodology
Chapter 4 of this study used data from the LATS and LTDS to determine the current levels of walking and cycling in London following the introduction of free bus fares. As with the previous outcomes we determined a counterfactual case using a comparison with the walking and cycling levels in the 25- to 59-year-old age group over the same period. The research identified that there was no significant change in the total distance walked following the introduction of the free bus fares (see Chapter 4). The study identified a small decline in the amount of cycling that the 12- to 17-year-old age group were
undertaking. Combined together (walking and cycling changes) there was no significant change in the amount of physical activity for the 12- to 17-year-old age group as a result of the policy, so no monetary value is included in the CBA framework.
One of the key methodologies that are available to determine the monetary value to society from changes in physical activity levels is the World Health Organization (WHO)130health economic assessment tool
(HEAT) methodology. In the documentation it states that:
HEAT should not be applied to populations of children, very young adults or older people since the available evidence was not sufficient to derive a relative risk for these age groups
p. 20130
Given this limitation of HEAT’s application, it should be noted that more research is required to allow an assessment of the monetary benefit to society of increases in walking and cycling for children as a result of an intervention. The current methodology as applied to adults can be found at the WHO130and the DfT.131
TABLE 18 Sensitivity test: decongestion benefits from the reduction in car (km)
Outcome Motorways (£) A road (£) Other roads (£) Total (£)
Total (excluding accident costs) mean –29,927 6,922,278 3,391,409 10,283,760
CI (maximum) –111,908 16,045,197 7,586,634 23,519,923
CI (minimum) –19,074 3,557,800 1,803,476 5,342202
Using the mean
Greenhouse gases 7482 106,333 94,424 208,239
Noise 1663 21,267 15,737 38,667
Local air quality 2494 31,900 23,606 58,000
Crime
The study hypothesised that there would be a change in assaults as a result of the intervention (see
Chapter 6). This section uses data from TfL and Chapter 6 to estimate the benefits from changes in assaults.
Methodology
Evidence from TfL indicates that crime rates on London’s transport network have declined over the period in which the intervention was implemented (Table 19), despite increasing numbers of bus trips. It has not been possible to split these data into crime type or to determine a counterfactual from these data. For example, it has not been possible to identify the age of the crime victims and so compare 12- to 17-year-olds with 25- to 59-year-olds.
Analysis was also carried out within the project using the HES data to determine whether or not there was a change in assaults associated with the intervention. It was hypothesised that an increase in bus trips could lead to an increase in assaults. The HES data were analysed using the assault rates in the same period to adults (25 to 59 years old) in London as the basis for the counterfactual. As shown in Table 20 this analysis resulted in the identification of an increase in assaults per year. However, the impact pathway is complex and it is difficult to prove causality (see Chapter 6). For this reason, this increase in assaults has only been included in the CBA framework as a sensitivity test.
Monetary values
The best estimate of the social costs of assaults on buses in England is provided by Home Office ‘social costs of crime’ evidence, adapted to public transport for DfT.133A weighted average value of £13,592 per
assault on buses and trams has been used, at 2009/10 prices. For the derivation see Table 21.
A proposal early in the study was to use the value for‘Serious Injury’ from DfT advice,126noting that the
definition of ‘Serious Injury’ by DfT126is:‘Serious injury: records casualties who require hospital treatment
and have lasting injuries, but who do not die within the recording period for a fatality’. Using the serious injury value, it was found that results would be an order of magnitude higher (> 10 times higher); however, the rationale for the assaults value is much stronger because it is much more specific to the
TABLE 19 Volumes of crime on the London transport network
Total crime (notifiable) 2008/9 2009/10 2010/11 2011/12
Bus 27,062 24,976 23,974 21,724
Tram 411 403 367 369
Underground/DLR 15,109 14,536 13,472 12,115
London overground 492 450 658 764
Source: Data compiled from TfL.132
TABLE 20 Counterfactual 2a: expected assault rates based on a statistical analysis of what happened in the same period to adults in the 25- to 59-year-old age group in London
No. of 12- to 17-year-old assaults (A); (2001–4) Observed no. of assaults post-period (B); (2006–9) Counterfactual: pre–post ratio of adult injuries (C) Expected no. of assaults under counterfactual (A × C) Change in assaults attributable to the intervention: observed– expected [B– (A × C)] Change in assaults per year 2321 3322 1.19 (1.16, 1.22) 2762 (2692.3, 2831.6) 560 (490.4, 629.7) 140 (122, 157)
outcome that has been measured. Therefore the results including the assaults value only (see Table 21) are provided as a sensitivity test.
Calculations
Using the monetary values in Table 21 and the change in assaults in Table 20 the results for inclusion in the sensitivity test are provided in Table 22. It indicates that the change in benefit to society is of the order of–£1.9M (mean) within a 95% CI of –£1.7M and –£2.1M.
In summary, the project explored the inclusion of changes in assaults as a result of the intervention. Unlike road safety, the major impact pathway is complex for crime, and it is difficult to demonstrate causality, as data were not directly linked to bus use, but admission to hospital. For this reason, the increase in crime observed after the intervention was introduced has been included as a sensitivity test.
Revenue
One of the consequences of the intervention is that those 12- to 17-year-olds who would have previously paid half-fare in 2009 are now travelling for free. This reduces the revenue that would be received by TfL. The methodology used to calculate the change in revenue is described next.
Methodology
In the‘do something’ scenario TfL will receive a revenue of £0 as those in the age group 12–17 years who previously paid to travel by bus now are exempt from paying. In order to determine the level of revenue in the‘do nothing’ scenario two counterfactuals were tested based on the results from the user benefit calculations. (For details on the calculation of the number of trips see User benefits.)
l Counterfactual 2a: expected bus travel based on a statistical analysis of what happened in the same period to adults in the 25- to 59-year-old age group in London (see Chapter 3).
l Counterfactual 2c: expected bus travel based on demand elasticities and TGF (see Balcombe and colleagues74).
TABLE 21 Derivation of a weighted average value per assault
Crime type Number of incidents Weighting by number of incidents
Estimated unit cost (£) (2006/7 prices) Costs of consequences of crime Costs in response to crime Total
Violence against a person (passengers) 39,390 0.85 3267 9923
Sexual offences 7004 0.15 6196 3556
Average (2006/7 prices) 3709 8962 12,671
Average (2009/10 prices) 13,592
Sources: Adapted from DfT133and HM Treasury.134
Note: Number of incidents includes multipliers for under-reporting.
TABLE 22 Sensitivity test: inclusion of social cost of assaults
Crime type
Change in assaults (see Table 16)
Estimated unit cost, £ (2009/10 prices)
Benefit of change in assaults, £ (2009/10 prices)
Mean 140 13,592 –1,902,900
CI (minimum) 122 13,592 –1,658,241
The calculations indicate that in the absence of the free fare, approximately 225 million journeys (netting £113M) would have been made by the 12- to 17-year-old age group within a 95% CI of £104M to £121M. Using counterfactual 2c this number is reduced to a loss of £103M.
Calculations
The results of this analysis are provided in Table 23. Using counterfactual 2a it is indicated that had the intervention not been in place that revenue of the order of £113M (within a 95% CI of £104M and £121M) could have been realised in 2009.
Note that the results below (see Bus operating costs) include a sensitivity test which incorporates both bus operating cost and revenue changes.