Yangon: A total of 20 people were killed and 159 injured in 58 traffic accidents on Myanmar's Yangon-Mandalay highway between January and April this year, according to a report from the Road Transport Administration Department on Thursday.According to Namibia Press Agency, the number of traffic accidents and fatalities on the highway this year decreased compared to the same period last year, which recorded 59 accidents, resulting in 33 deaths, the report said.On Thursday, the state-owned Myanmar Radio and Television reported that the major cause of accidents on the highway during the period is human errors, as well as vehicle defects such as tire blowouts during the hot season.The 587-km Yangon-Mandalay expressway connects the country's commercial city of Yangon and the second-largest city of Mandalay.