[sustran] NMT Travel Time Value

[Christopher Zegras]

Hello, 

It is common practice in transport planning to assign travel time by
Non-motorized modes (walking and bicycling) a higher cost than travel time
by motorized modes.  For example, the oft-cited United Kingdom Dept. of
Transport research on the the value of travel time recommends that biking
and walking (as well as waiting times for public transport) should be given
a travel time value 2 times higher than that by motor vehicle.  In Chile,
the planning ministry recommends valuing wait time as 1.5 times as high as
vehicle travel time and biking and walking as 2 times as high.

>From what I understand, this valuation attempts to reflect the displeasure
of these modes relative to motorized modes.  In other words, a typical
trip-maker would prefer to travel by auto instead of foot -- all other
things being equal -- because the travel time by foot is costlier.  So, even
if a car and pedestrian travelled at the same speed (which is the case in
some places at some times), a typical trip-maker would rather travel by car
than by foot, since foot travel is perceived as more expensive.  Is this right?

My question is this:  does anyone know of any specific references to what
components of NMT travel time (or waiting time for public transport) make
the perceived cost so high?  Have any attempts been made to disaggregate NMT
or waiting times to show, for example, that 10% of the extra cost of NMT
travel time is due to accident risk, or sweat, etc.  Have any attempts been
made to quantify reductions in perceived time costs by NMT improvements
(i.e., through traffic calming measures, bikelanes) or improved waiting
conditions (i.e., improved transit information technology)?  Can this be done?

Any leads, references, comments would be most appreciated.  I apologize for
any cross-postings.

Regards, 

Chris Zegras
 Christopher Zegras       http://www.iiec.org                 /\   /^\
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