一応ルールでは"Strollers must be collapsible."となってますけど、皆さんご指摘の通りドライバーによってまったく対応が違いますね。
http://www.translink.ca/en/About-TransLink/Media/2007/July/TransLinks-Policy-for-People-with-Disabilities.aspx # Seats at the front of buses – trolleys, 40’ conventional and 60’ articulated coaches – can flip up to accommodate people with mobility devices. Please vacate these seats immediately and help make room for them.
# Strollers may use this area; however, when demand dictates, the stroller must give way to people with mobility devices, including walkers. Children in strollers should be removed and the strollers collapsed.
# For safety reasons, the maximum size for a stroller is 122 centimetres (48”) long by 60 centimetres (24”) wide. Strollers must be collapsible.