The state is pushing to start collecting tolls on the SR 520 floating bridge as early as November of next year, but the start date could be delayed until June 2011.

The key, state officials say, is how potential contractors respond to an incentive program that encourages them to design a system to collect tolls. The sooner contractors can implement a plan to collect tolls before June 2011, the more money they can get from the state.

Contract proposals are due on September 29, WSDOT officials say. A key part of the bidding and contract selection process is an incentive program that encourages vendors to open the center as soon as possible.

The sooner they propose to open (between November 2010 and June 2011), the more incentives they can earn. The contractors also will face fines (called liquidated damages) if they fail to meet the contracted completion date.

Incentives for early delivery call for $100,000 per week with a cap of $3 million. The liquidated damages will cost the chosen vender $350,000 for every week they overshoot the contracted completion date.

Proposed tolls on the SR 520 bridge will vary based on the time of day. The more congested the bridge, the higher the toll. One-way tolls are seen ranging from around $2 to $3.25. Tolls also are being considered on I-90, particularly if motorists switch from SR 520 to avoid paying a toll there.

The money collected will go toward the estimated $4 billion cost to replace the current SR 520 floating bridge. The bridge opened in which opened in 1963 and is at risk of sinking in a severe windstorm. Today it carries far more vehicles than it was designed to accommodate.