Latest analysis suggests that the distance travelled by local bus services in Wales has fallen by 20% in 10 years.
The BBC has reported that Department for Transport statistics also suggest that the number of miles covered with financial support from local authorities has almost halved.
However the Welsh Government called the figures 'misleading' as other factors are involved, including a rise in train journeys. It also highlighted that the figures do not include longer-distance TrawsCymru services.
Wales has seen the biggest percentage drop in bus miles (between 2006-2007 and 2016-2017) compared to the other UK nations.
The Welsh Local Government Association (WLGA) said: 'A steady decline in bus usage unfortunately undermines the case for continued financial support for non-commercial services.'
The news comes after a string of bus companies in Wales have collapsed, while networks have been reduced across the UK in the face of tough financial challenges for local authorities.