David Crawford looks at the sunny side of the street. Solar power has been relatively slow in entering the transport sector, but a current blossoming of activity bodes well for the large-scale harnessing of an alternative energy that is zero-emission at source and, in practical terms, infinitely renewable. Traffic management and traveller information systems, and actual vehicles, are all emerging as areas for deployment. Meanwhile roads themselves are being viewed as new-style, fossil fuel-free ‘power stati