Pro-viaduct radio ad: Do the claims measure up?

The pro-viaduct campaign has a lot less money than its opponents, but it does have a 30-second radio ad that started running Tuesday.

The No Tunnel Alliance, which supports a new viaduct, has spent $15,000 to place the ad on KOMO, KIRO, KVI and other stations.

Here's an assessment of the some of the ad's claims.

Claim: "A quieter, safer viaduct will be paid for by the state."

Analysis: This is largely accurate. State officials have said they would pay for a new six-lane $2.8 billion viaduct, which would be safer than the existing earthquake-damaged structure.

But it's not clear that a new viaduct would be quieter. The state's environmental-impact study says it would be as loud as the existing structure. State officials and the pro-viaduct campaign say innovations, such as quieter pavement and sound-absorbing panels, could make a new viaduct quieter than the existing one. But there's no guarantee they will be used.

Claim: "Other options cost Seattle taxpayers billions."

Analysis: This is not clear. A new viaduct is estimated to cost $2.8 billion; the tunnel proposal on the ballot is estimated at $3.4 billion. The cost difference between the two, which Seattle would pay for under Mayor Greg Nickels' plan, is not "billions."

Gene Hoglund, manager of the No Tunnel Alliance campaign, says overruns would likely drive a tunnel's cost far above $3.4 billion.

David Dye, a top state transportation official, said last month the $3.4 billion figure is probably optimistic. But the state Department of Transportation has not provided a tunnel cost estimate, saying there hasn't been enough time.

Hoglund also says tearing down the viaduct -- and using surface streets and improved transit in its place -- would cost Seattle taxpayers more than $1 billion because state Senate Transportation Committee Chairwoman Mary Margaret Haugen, D-Camano Island, has said legislators would likely contribute $1 billion less to the surface option than they've pledged for a new viaduct.

Claim: "Say 'yes' to the elevated. Move traffic, save money, save lives."

Analysis: A new viaduct would save money compared with a tunnel option.

It would also be safer than the existing viaduct, surviving potential earthquakes the current structure couldn't withstand.

Hoglund also says an elevated highway would have fewer collisions and fires than the mayor's tunnel plan, in which the safety shoulders would be used as rush-hour exit lanes.

The state DOT said last month that emergency vehicles would have trouble reaching accident scenes, but outside experts say speeds can be lowered to reduce the likelihood of severe collisions, and reduced-size highways in other places have operated safely.

Staff reporter Mike Lindblom contributed to this report.

Bob Young: 206-464-2174 or byoung@seattletimes.com