%0 Journal Article %T Safety evaluation of visual load at entrance and exit of extra-long expressway tunnel based on optimized support vector regression %A Shang, Ting %A Lu, Hao %A Lu, Jiaxin %A Fan, Jing %J PLoS ONE %V 17 %N 8 %D 2022-08-04 %I Public Library of Science %~ DeepDyve