The number of people killed or seriously injured on the roads of Brighton and Hove soared last year, but officials do not know why.
The latest figures from the Department for Transport show that the city bucked the national trend of a reduction in the number of serious crashes.
Overall in England and Wales the number of people killed or seriously injured in crashes fell by 2% in 2011.
But Brighton and Hove saw a 26% increase.
Across Sussex, 5,240 people were injured in traffic accidents in 2011, of whom 70 were killed.
Brighton and Hove suffered 1,106 casualties, the highest of any council area in the county.
There were 172 people killed or seriously injured in accidents in the city, including 16 children.
In total, six people died on the roads in Brighton and Hove during the year, slightly less than the average each year from 2005 to 2009.
Sussex Safer Roads, the police and council partnership set up to reduce accidents, said it could find no clear explanation for the rise and that it was most likely an “unfortunate year”.
It stressed that although the number of people killed or seriously injured had risen, overall accident levels had fallen.
Reduction this year
A spokesman for the partnership said: “There are no clear-cut reasons for the increase.
“We are fortunate in that Brighton and Hove sees relatively low casualty numbers, compared to the size of population, both residential and visiting, and traffic on the roads.
“However we will continue to enforce and educate as appropriate |to bring the number of people killed or seriously injured on the roads down.”
He added that figures for this year appear to show a reduction compared to 2011.
Mid Sussex had the second highest number of children seriously injured on the roads, but its total of eight was half that of Brighton and Hove.
There were 8.4 crashes per 1,000 licensed vehicles in the city compared to a rate of less than half that across East and West Sussex.
A quarter of accidents in East Sussex took place on wet or flooded roads but just a tiny proportion of accidents across the county took place on snowy and icy roads.
Across Sussex 70 people died on the roads during the year.
Traffic police described June 2011 as the bloodiest month on the county’s roads for five years, with 13 deaths during the month.
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