What crucial capability did Mitsubishi's 1995 'Preview Distance Control' system still lack?

Answer

Ability to apply the brakes

The 1995 laser-powered system could control speed via throttle or downshifting, but it required the driver to handle the actual stopping action.

What crucial capability did Mitsubishi's 1995 'Preview Distance Control' system still lack?
inventorVehicletechnologysystemadaptive cruise control