Hybrid Arctic all-electric mode?

[Scionic]

I live on Foster, a couple miles east of the North Park garage.  It's 24-hour parade of buses past my front window.  They are usually going unnecessarily fast down the street, but that's another thread.

A hybrid artic (number 43-something-something) just went past, followed by a CTA supervisor SUV, both going very slowly, maybe 5mph.  The bus had its interior lights off, and didn't appear to have the diesel engine running.  Can those buses run on an all-electric 'limp mode' in case of diesel motor failure?  I know some hybrid cars have this option, with a very limited range.

[briman94]

I live on Foster, a couple miles east of the North Park garage.  It's 24-hour parade of buses past my front window.  They are usually going unnecessarily fast down the street, but that's another thread.

A hybrid artic (number 43-something-something) just went past, followed by a CTA supervisor SUV, both going very slowly, maybe 5mph.  The bus had its interior lights off, and didn't appear to have the diesel engine running.  Can those buses run on an all-electric 'limp mode' in case of diesel motor failure?  I know some hybrid cars have this option, with a very limited range.

In both our hybrid cars, the ignition has to be on to run at all, which means the engine can be on, and since the hybrid buses don't shut their engine off at all, I would think it would have to have the engine running for it to count as "on" but I could be wrong. Maybe if the engine dies the hybrid system can still be on and it can move slowly on battery-only mode. My dad's car can go about 35 MPH for a mile or two with no engine, but I'm not sure what the batteries on a bus would allow. It's really a matter of what the computer system lets it do.

[MTRSP1900-CTA3200]

...A hybrid artic (number 43-something-something) just went past, followed by a CTA supervisor SUV, both going very slowly, maybe 5mph.  The bus had its interior lights off, and didn't appear to have the diesel engine running.  Can those buses run on an all-electric 'limp mode' in case of diesel motor failure?  I know some hybrid cars have this option, with a very limited range.

I'm not sure about here, but hybrid buses run in Seattle through their transit tunnel all the time, where diesel exhaust would not be desired. They feature a "Hush Mode" (info can be found on this page). This places more demand on just the electric motors and batteries. While the diesel engine is still used at points, it is used far less than when the buses are running normally. Again, I'm not sure about when the motor fails though.