Over here in Ireland they're almost exclusively sodium lamps except in some city centre locations where an orange glow is considered a little on the ugly side and a white flourecent or high powered "architectural" white uplighters are used on buildings and bridges.
Old lamps were mercury based and were gradually phased out as they're considered an environmental hazard. Disposal of large quantities of mercury containing tubes poses a big problem and is quite expensive.
The older mercury lamps also didn't really throw out enough light. Sodium bulbs can be much brighter without being irritating.
