The necessity of constructing low carbon society has been widely noticed in these
days. The CO2 emission from automobile is not small, so that a modal shift from automobile to bicycle
is one of the challenges toward the low carbon society. However, this kind of modal shift has
not progressed enough. This reason can be supposed because there are some disincentives against
it. In this study, therefore, the disincentives are first categorized into five groups, then three policies
such as (a)introduction of bicycle highway, (b)lease system of power-assisted tricycle and (c)grant for
purchasing new bicycles have been proposed based on the categorization under the preconditions of
parking bicycles in conventional automobile parking lots and no change of commuting allowance in
order to surmount the disincentives. In addition, a questionnaire survey was conducted to evaluate the
proposed policies. As the results, the following facts were found; (1) Proposed policies are all useful,
especially (a) introduction of bicycle highway is the most. (2) The disincentives against accidental risk
and serious weather can not be surmounted by the proposed policies, and the disincentive related to
their clothes and climate should be considered.