Summary of λ parameters

To conform to the conditions of use specified by the MoT, three levels of sample validity are defined and are highlighted in the following tables of travel time distribution results. Conditions specify that trends can only be established from data samples containing more than 120 trip legs or 60 persons. As this analysis combines multiple trip legs into trip chains, a secondary limit of 90 trip chains has been proposed when identifying insufficient sample sizes. The three levels of validity displayed in the following tables are:

1      Valid. Curves fit to data containing more than 120 trip legs and more than 90 trip chains.

2      Indicative. Curves fit to data containing fewer than 120 trip legs but more than 90 trip chains; indicated by underlined type.

3      Provided only for reference. Curves fit to data containing fewer than 120 trip legs and fewer than 90 trip chains; indicated by boldface italic underlined type.

The final two categories contravene the MoT conditions of use and should only be used for reference, in conjunction with other sources of information[9] or in the context of other results presented in this research that feature an adequate sample size. Blank cells in the following tables indicate there were either no samples or an insufficient number of samples for a trend to be developed.

λ parameters for the assessed activities, categorised by area types, for walking and cycling travel are summarised in table 13.2. λ parameters for travel as vehicle driver and vehicle passenger are displayed in table 13.3, while those for local public transport are shown in 13.4. The λ parameter determines the rate of decay of the curve. A small λ parameter has a lesser rate of decay than a large λ parameter; hence, fewer short duration trips and a greater proportion of longer duration trips.


Table 13.2    Walking and cycling λ parameters

Destination activity

Walking

Cycling

MUA

SUA

RA

MUA

SUA

RA

l

R2

l

R2

l

R2

l

R2

l

R2

l

R2

Employment

0.065

0.93

0.069

0.91

0.144

0.91

0.060

0.82

0.084

0.82

0.047

0.75

Primary school

0.101

0.89

0.119

0.74

0.147

0.79

0.094

0.62

0.119

0.90

0.146

0.79

Intermediate school

0.077

0.93

0.056

0.76

0.110

0.86

0.085

0.78

 

 

0.142

0.76

High school

0.057

0.84

0.056

0.88

0.076

0.81

0.073

0.78

0.106

0.87

0.087

0.99

Tertiary education

0.061

0.68

 

 

0.100

0.86

0.081

0.87

 

 

 

 

Shopping

0.100

0.96

0.080

0.91

0.097

0.97

0.122

0.87

0.168

0.59

0.151

0.78

Other

0.092

0.98

0.089

0.93

0.144

0.96

0.090

0.95

0.104

0.72

0.088

0.93

Recreation

0.066

0.94

0.066

0.86

0.063

0.96

0.053

0.96

0.047

0.98

0.046

0.97

All activities

0.077

0.97

0.074

0.93

0.090

0.98

0.069

0.94

0.080

0.89

0.065

0.95

 

Table 14.3    Vehicle driver and vehicle passenger λ parameters

Destination activity

Vehicle driver

Vehicle passenger

MUA

SUA

RA

MUA

SUA

RA

l

R2

l

R2

l

R2

l

R2

l

R2

l

R2

Employment

0.068

0.88

0.086

0.95

0.064

0.98

0.071

0.87

0.063

0.95

0.049

0.97

Primary school

 

 

 

 

 

 

0.118

0.92

0.180

0.71

0.117

0.93

Intermediate school

 

 

 

 

 

 

0.101

0.90

0.267

0.43

0.129

0.94

High school

0.067

0.83

 

 

0.066

0.73

0.087

0.89

0.137

0.85

0.088

0.95

Tertiary education

0.063

0.90

0.110

0.87

0.060

0.97

0.052

0.92

 

 

0.044

0.94

Shopping

0.119

0.92

0.166

0.90

0.072

0.98

0.095

0.92

0.130

0.90

0.044

0.98

Other

0.079

0.96

0.118

0.94

0.059

0.96

0.074

0.96

0.066

0.78

0.053

0.97

Recreation

0.073

0.95

0.089

0.94

0.060

0.98

0.065

0.96

0.047

0.70

0.039

0.96

All activities

0.080

0.94

0.104

0.95

0.064

0.98

0.080

0.095

0.075

0.87

0.053

0.97

Table 13.4    Local public transport, bus and rail, λ parameters

Destination activity

Local bus

Local rail

MUA

SUA

RA

MUA

SUA

RA

l

R2

l

R2

l

R2

l

R2

l

R2

l

R2

Employment

0.036

0.70

 

 

0.012

0.75

0.019

0.59

 

 

 

 

Primary school

0.060

0.87

 

 

0.047

0.69

 

 

 

 

 

 

Intermediate school

0.039

0.65

 

 

0.041

0.42

 

 

 

 

 

 

High school

0.034

0.51

0.046

0.30

0.036

0.74

 

 

 

 

 

 

Tertiary education

0.027

0.62

 

 

 

 

 

 

 

 

 

 

Shopping

0.037

0.79

 

 

 

 

 

 

 

 

 

 

Other

0.036

0.78

 

 

0.042

0.63

 

 

 

 

 

 

Recreation

0.036

0.63

 

 

 

 

 

 

 

 

 

 

All activities

0.037

0.76

0.061

0.66

0.041

0.76

0.021

0.67