Ie bendy busses. We've had a multi year argument running on reddit here in Brisbane about a very expensive trackless "metro" which is just.. articulated buses with wheel covers
Well, the argument that article provides relating to advantages over buses is compelling at the fave value: “Until recently, the options for this mid-range transportation (we call it 'mid-tier transit') were limited to light rail, which is very expensive, and bus rapid transit, which is rarely electrified and is often stuck in traffic. The mid-tier transit we need is trackless tram technology: less costly than light rail, faster and sleeker than buses, carbon-neutral and flexible. Installing trackless trams in the middle suburbs can improve access to public transport, reduce emissions, increase land value and encourage more people to move to these areas. “