During his tenure, Liu's ministry was criticized for its illegitimate business interests and relationships with large companies, its inability to improve conditions for migrant workers during the Chinese New Year travel season, its slow response to widespread winter storms in 2008, and its failures to prevent the 2008 train collision in Shandong and a smaller collision in Hunan a year later. In addition, Liu was personally subject to online criticism for his repeated marriages. Illegal subcontracting was a common practice throughout Liu's tenure as head of the rail ministry, so that much of the staff who built the railway were poorly educated, trained, and supplied.