<p>The New Zealand government is using a tax windfall to put an extra $500m into improving the transport network.</p> <p>Transport minister Pete Hodgson said it is determined to fix the infrastructure deficit created by the last national government.</p> <p>There are no details yet about how the money will be spent.</p> <p>Finance minister Michael Cullen said the higher tax take is a result of the financial industry responding to new tax law. </p> <br />