请帮忙翻译这句短语

现在已经开始建设沪杭城市高速铁路，竣工通车以后，从南山乘火车到上海只需要四个半小时，到南京只需要两个半小时，非常方便”

Now the construction of the high-speed city railroad from Shanghai to Hangzhou is started.After the project is completed,it will only take four hours to travel from Nanshan to Shanghai by train.And it will be only two and a half hours to go to Nanjing.It is absolutely convenient.

1L机翻，2L有点不太详细

Now already started to construct the Shanghai-Hangzhou city high-speed railroad, after completion is open to traffic, from Mt. Nan goes by train to Shanghai only to need for four-and-a-half hours, only needs to Nanjing for two-and-a-half hours, is convenient.