Sound Transit delivered on a promise to bring commuter rail service to Snohomish County by the end of 2003.

Even so, the deal for access to Burlington Northern Santa Fe Railway tracks isn’t entirely sewn up yet.

In the rush to get Sounder service started by the self-imposed year-end deadline, Sound Transit and Burlington Northern agreed to sort out the final details of their agreement after the start of the year.

Those finishing touches have been announced, and they will cost Sound Transit an extra $8 million in taxpayer money. The Sound Transit board is scheduled to vote today on the newer, more expensive Sounder budget.

Overall, the cost of Everett-to-Seattle Sounder service has grown from $385 million to $393 million.

Also, the $24 million annual cost of operating the entire Sounder system is up $826,000 because of changes to the Everett-to-Seattle contract.

Agency officials say they expected the bill to grow from the original $385 million announced at the end of last year, while critics say the cost overrun is another example of the agency’s legacy of escalating costs.

Sounder service to Snohomish County was supposed to cost $177 million and include seven round-trip trains each weekday.

Negotiations with the railroad and faulty cost estimates ballooned that amount to $385 million, and now $395 million.

The price for access shot up when Burlington Northern balked at giving up access to its main line to the East Coast, something that wasn’t as critical south of Seattle when Sound Transit negotiated for access on the railroad’s line to Tacoma in the late 1990s.

So far, about 300 people a day have been riding Sounder’s lone round-trip train to Seattle and back, said Lee Somerstein, a Sound Transit spokesman.

Sounder’s Everett-Seattle service offers a weekday train leaving Everett Station at 6:55 a.m. and arriving in Seattle’s King Street Station at 7:54 a.m. And a return trip leaving Seattle at 5:15 p.m. and arriving in Everett at 6:14 p.m.

Reporter Lukas Velush: 425-339-3449 or lvelush@heraldnet.com.