Is it a bus or a train? The new tram envisioned for California State University Sacramento would be a little of both. The idea is called “bus rapid transit,” and backers hope it could remove some 5,000 cars a day from the congested campus. It would use clean-energy vehicles with rubber tires – like a bus – but have subway-style doors and a dedicated route – like a light-rail train. It would run on ordinary pavement on and around campus and connect to light rail. The school has set an ambitious schedule to launch the service by 2010, but first it needs some cash. The Sacramento Area Council of Governments granted $924,000 to design the system, and the school is awaiting a decision next month from the California Transportation Commission for additional design funding. The next hurdle is to line up $20 million to actually build the system.