Amtrak has unveiled a new top tier to its frequent traveler elite-level program.

Guest Rewards members who earn 10,000 points or more annually will be admitted to the new “Select Plus” level, beginning March 1.

Benefits include a 50-percent bonus on all rail travel, unlimited access to ClubAcela, Metropolitan, and First Class lounges, single-class upgrades available 48 hours in advance, and companion coach vouchers.

Amtrak also is beefing up benefits for its existing Select tier, which requires 5,000 points annually, giving members coupons good for one-day lounge passes or 10 percent off regional or long-distance trains and single-class upgrades available one hour in advance.

Finally, the overall Guest Rewards program will also be altered this year: Travelers will still get two points for every dollar spent on Amtrak travel, but also will receive at least 100 points per one-way trip, and free travel will be available for as little as 1,000 points.

Savvy travelers have been aware of Amtrak’s Guest Rewards program for some time. Even many who rarely, if ever, travel by train use the Amtrak Guest Rewards MasterCard, which has no annual fee, and earns one point per dollar spent. As such, it is one of the better mileage-earning values available, since Amtrak points convert one-to-one with Continental OnePass miles, Midwest Miles, and United Mileage Plus miles (up to 25,000 a year).