TransLink is mulling a one-zone fare for buses when the Compass cards are deployed.

The beleaguered $200-million Compass card system is supposed to stop fare evaders and make riding transit easier, but testing shows the card readers are too slow and inaccurate.

In particular, the transit agency is having trouble with the Compass card's tap-out function on buses, which would determine how many zones a rider has travelled. Instead of properly reading the card, the card validators take too long to tap off — potentially creating lineups as riders leave buses — and riders who forget to tap out could be charged for three zones.

A one-zone fare would be one potential solution to TransLink's tap-off system. It is also considering a grace period as riders get used to the new program.

TransLink estimates 220,000 customers will be using the much-delayed cards by September on the West Coast Express, still far short of the company's 850,000 goal.

Take the poll: Would you get a Compass Card if there was one-zone fare for buses?