VISALIA -- Measure R, a half-cent sales tax approved by Tulare County voters for road and transportation projects, has generated almost $5 million more in its first year than backers expected.

The measure was passed in November 2006 and took effect in April 2007. By last month, about $26.4 million was collected -- well over the $21.7 million that was originally projected by the Tulare County Association of Governments.

Tulare County Supervisor Phil Cox said the 21% difference is largely due to conservative revenue estimates used to project sales taxes in the county. "We used one-year-old numbers, and we purposely did not build any growth into the revenue plan. So even if our growth slows next year, we're still ahead of our projections."

"But we didn't anticipate the revenues being this strong," Cox added.

The increase comes even as Tulare County -- like other areas of the state -- is gripped by a sluggish economy. But when things cost more to buy, they also generate more sales tax. For each $10 spent on retail merchandise and services -- just about anything except food groceries for home use and prescription medications -- Measure R reaps a nickel.

"The additional money just increases what we are able to do with Measure R," said Ted Smalley, executive director of the Association of Governments.

Cox said the unexpected cash not only provides more money to each of the Tulare County cities that get a bite of the Measure R pie, but also allows the countywide authority to move road projects ahead of schedule on the spending timeline.

Visalia, for instance, was originally projected to receive $1.6 million in funds for city road and transportation plans in the 2007-08 budget year; instead, Measure R provided the city with nearly $2.1 million. Tulare saw its Measure R share jump from an expected $692,000 to more than $867,000.

The county association, which doubles as the Tulare County Transportation Authority that oversees Measure R spending, will receive a full report on Measure R at its meeting Monday in Tulare.