There are 18,337 street lights in Carmarthenshire
Carmarthenshire is set to become the latest council in Wales to switch off street lights to save money.
A review is under way into the 18,337 lights in the county that cost about £560,000 a year to run.
The council said it would look at different options such as turning some off between 0030 and 0530 GMT.
Similar cost-cutting measures in other areas including Pembrokeshire, Torfaen and Powys have been criticised by some residents and motoring organisations.
Carmarthenshire said some town and community councils in the county were already operating part-night lighting to reduce costs.
It said a working group would look at various proposals taking into account rising energy costs, potential carbon savings and community and road safety risks.
The group will also speak to other local authorities that have implemented part-night lighting.
Group chairman Jim Jones said: "The group will carefully consider proposals for the council's public lighting network.
"It is vital that we make financial savings, as well as reduce the council's carbon footprint.
"A consultation exercise will be undertaken in a bid to find the most suitable proposal for Carmarthenshire."