As of now there is a ban on all air, rail, coach and ferry travel to Latvia, unless exemptions have been granted by an appropriate government minister - which will be the case with special repatriation services on land, sea and air to bring Latvian nationals home from other countries.
The border with neighboring European Union countries Estonia and Lithuania may in theory be crossed by people on foot or using their own private transport, but with other countries imposing new border rules of their own, there is no guarantee they will be let into those countries.
Crossing the Lithuanian border is currently possible only in three locations - Grenctale, Medums and Rucava. On the Estonian border the crossings are at Ainaži, Unguriņi, Valka and Veclaicene.
On the eastern borders with non-EU states Russia and Belarus, restrictions are even stricter with private transport stopped in both directions, apart from Latvian residents returning home and foreign nationals leaving.
However, goods vehicles and their drivers may still enter and leave Latvia to keep supplies and trade running as much as possible.
The full details of the emergency measures imposed to slow the spread of the coronavirus can be read at the official Latvian government website.
The key sections regarding border travel read:
International passenger transport through airports, ports, by bus and rail transport will be cancelled as of 17 March. In addition, the movement of persons and vehicles through airport, port, railway and road border crossing points at the European Union’s external border, as well as at border crossing points intended for local border traffic will be banned from 17 March 2020. This prohibition will not apply to the carriage of goods.
The above-mentioned restrictions to travel through airport, port, railway and road crossing points shall not apply to nationals of the Republic of Latvia who wish to return to Latvia.
Nor do they apply to foreign nationals whose permanent place of residence is in Latvia and who want to return here or to foreign nationals who want to leave Latvia.