Table 4 Input parameters for estimation of intervention effect, mean value and 95% uncertainty intervals

Cross price elasticity for PT with respect to fuel price

0.07

Derived increase in the prevalence of PT commuting of 0.61% [38]. Modelled to PA/BMI effect (Appendix 3). Assumed all new PT users were previous car drivers, a reasonable assumption given the high prevalence of driving to work in Australia [38].

Average annual retail fuel price (national, metropolitan)

(cents per litre)

125.39 cents

(95% UI 124.95–125.86)

Sampled from a gamma distribution, from national metropolitan fuel price [102].

Marginal MET^b value for walking to access PT

2.5

(95% UI 0.7–6.4)

MET value for walking to access PT 3.5 from Ainsworth et al. 2011 [81], adjusted for inactivity. Sampled using a lognormal distribution (stdev 1.6 from Gotschi et al. 2015 [103]).

Average distance a person will walk to access PT (metres)

400

Based on ‘rule of thumb’ planning guideline for distance walked to bus/tram access points [104, 105].

Comfortable gait speed (cm/s)

Males

18-29y = 139.2

(95% UI 110.5–172)

30-39y = 145.7

(95% UI 128.4–164.2)

40-49y = 145.6

(95% UI 115.6–180.4)

50-59y = 139.5

(95% UI 100.5–192.2)

60-64y = 136.3

(95% UI 100.9–179.7)

Females

18-29y = 140.3

(95% UI 109.3–177.4)

30-39y = 140.8

(95% UI 117.5–166.9)

40-49y = 139.2

(95% UI 111.5–172.1)

50-59y = 139.5

(95% UI 112.2–170.8)

60-64y = 129.6

(95% UI 90.8–172.7)

Sampled from a lognormal distribution, taken from estimates from Bohannon 1997 [106]. Using average distances and gait speeds this results in an average increase in walking to access PT of 18.9 min per day in men and 19.2 min per day in women. This falls within the range summarised by Rissel et al. [30] of 8 to 33 min PA associated with PT use.

Number of weeks of intervention effect (averaged over year)

49

(95% UI 46–52)

Sampled from a uniform distribution based on estimate of number of working weeks per year for full-time workers.