Amtrak has a sale on fares between Washington and Baltimore to New York City for travel from March 13 to April 4.

One-way coach fares are $40 from Washington and $36 from Baltimore. The special fare is only available through Thursday.

The fare, which the promotion says can’t be combined with business class upgrades, is only available on Northeast Regional service and fares are non-refundable, although exchanges before departure will be permitted.

Amtrak’s coach rates between Washington and New York normally begin at $49 with advance purchase. A search of some dates revealed that the special fare may apply to a limited number of routes, or some seats may already have sold out.

Check out the details on the Amtrak Web site.