Research Idea Details

Research Idea Scope

In the USA’s 374
metropolitan areas of 50,000 population and above, there is a significant
variation in the rate of road-based passengership (being a passenger in a car,
van, or bus) when traveling to work.  In
high passengership metro areas as many as 18.8% of all road-based commute trips
are taken as a passenger.  In low
passengership areas the statistic is as low as 4.2%. 

Some of this variation
will be specific to the communities, perhaps their physical layout, land-use
policies, or industries.  Some will be
caused by differing approaches to management of the transport system.  Either way, some corridors are getting a much greater amount of mobility bang for their transportation buck.  There is limited understanding of the causes of these differences and a significant study is called for. 

Such a study would lead to
a framework for developing interventions in low-passengership corridors to help
raise passengership rates and reduce vehicle trips without reducing
mobility. 

Follow-on research would
create a program of sustained experimentation to learn how to bring
improvements to low-passengership corridors.

This proposal looks at all
road-based passengers as being equal – they have the same impact on the traffic
if they would otherwise be drivers.  We
will never understand congestion if we do not understand the reasons for this
variability.

The usual approach to
ridesharing research is to look at carpooling and vanpooling programs that are
in place to encourage ridesharing, usually in isolation of other factors.  The reality is that most such programs have a
very miminal impact on the total number of ridesharing trips. 

This research should
consider a broad range of factors such as the geography of the metro area, the
extent to which it is polycentric, the transportation market and the way it has
developed, the extent to which there has been state support for ridesharing
initiatives, funding for transit, the culture of the city, the orientation
towards cars, the pricing of parking, and a multitude of other factors that
could influence the development of a passengership culture vs a drive-alone
culture.

It is not clear that this
research truly fits in the MAP-21 focus area. 
It is perhaps most properly ‘System Operations’, but that is not an option
in the focus area list.  On the other
hand MAP-21 has performance measurement and management requirements to reduce
congestion, and this project will begin the critical work that will lead
towards this goal.

Urgency and Payoff

If all metro areas equaled
the rate of passengership in Honolulu, there would be 9.2 million fewer
vehicle-round-trips PER DAY across the USA (about a 9% reduction in to-work
vehicle trips).  While it is not likely
the project would cause such a change, it is seen as the very important first
step in understanding how to begin to reduce drivership rates. 

The environmental,
economic, infrastructure and energy consumption impacts of 9.2 million fewer
daily vehicle-round-trips would be huge. 
Over time, any shift away from a drivership culture towards a
passengership culture will have positive environmental benefits.  The urgency of the work is that without this
understanding the intransigent problem of traffic congestion will never be dealt
with.