Stagecoach and First buses are making temporary changes to services across Yorkshire from Monday.
It's following the government advice to limit non-essential travel.
In a statement they said: "We’re making temporary changes to our services and timetables from Monday 23 March. The changes ensure that essential routes are maintained wherever possible. The changes will vary by region depending on the local needs of our communities. We are currently reviewing services in all regions so please bear with us while we finalise the timetables."
It comes as concessionary travel passes for older people can temporarily be used on all buses and trams in South Yorkshire before 9.30am - any day of the week.
The government has also agreed with rail operators they can reduce service levels from Monday following a drop in passenger demand.
The COVID-19 outbreak means numbers are down around 70% across the UK.
Services will be scaled down progressively across the network and kept under review.