Twilight (Or Unknown) : Road Transport - Accidents. A residual category covering cases where daylight conditions were very poor or where no information on light conditions was available
Glossary for transport statistics (Railway Transport, Road Transport, Inland Waterway Transport, Oil Pipeline Transport, Maritime Transport), 3rd Ed., Prepared by the Inter-secretariat Working Group on Transport Statistics, European Conference of Ministers of Transport, United Nations, Luxembourg, 2003. http://epp.eurostat.ec.europa.eu/cache/ITY_OFFPUB/ KS-BI-03-002/EN/KS-BI-03-002-EN.PDF (Transp - Brit) {528}