JEFFERSON CITY – Missouri officials pledged Wednesday to rebuild hundreds of bridges, pave thousands of miles of roads and improve dozens of airports and sidewalks around the state if voters approve a transportation sales tax next month.

The state Highways and Transportation Commission endorsed a list of more than 800 projects totaling $4.8 billion that would be funded over the next decade by proposed Constitutional Amendment 7.

Improvements in the Kansas City area include improvements to Interstate 70 in Independence, replacing the Interstate 435 bridges over I-70 near the stadiums, a new Broadway Bridge in Kansas City, and funding for streetcar and commuter rail plans. Also, the biggest item overall is the widening of I-70 to six lanes from Missouri 7 in Blue Springs east to Wentzville, making it six lanes across the state.

The Aug. 5 ballot measure asks voters whether to impose a three-quarter cent sales tax for transportation. Ninety percent of that money would go to the state, but local governments would get an estimated $540 million over a decade for their own projects.

Without more money, the Missouri Department of Transportation has said that it soon will be strained to maintain existing roads and won't be able to undertake major new projects.

The proposed sales tax “is a once-in-a-generation opportunity,” said transportation commission Chairman Steve Miller.

MoDOT, working with the Mid-America Regional Council in Kansas City, had previously released metro area proejcts. In its final list, it kept all of those projects and added some. Those projects include:

• Replacing the bridges that carry Interstate 435 over I-70 near the stadiums. Left-hand exits would be eliminated, and I-435 would flow through that intersection with six lanes all the way. Cost: $41.75 million.

• Adding “auxiliary lanes” – the shoulder, in other words – on I-70 at five bridges. Each bridge – Pittman Road, Blue Ridge Boulevard, Crysler Avenue, the Union Pacific Railroad line and Phelps Road – would be replaced by a longer one, allowing the space for the added lanes. Cost: $75.13 million.

• Replacing the Broadway Bridge, which carries U.S. 169 over the Missouri River in Kansas City. MARC last month put that cost at $150 million, though the final project list shows MoDOT kicking in just $73.83 million from the sales tax.

• Adding lanes to I-435 from the Grandview Triangle to the Kansas line. Cost: $81.08 million.

• Several projects in Lee’s Summit – $45.05 million to upgrade the intersection of I-470 and U.S. 50; $5.82 million, plus an $8 million city match, to upgrade the intersection of Missouri 291 and U.S. 50; and $1.73 million for the airport.

• MoDOT added money for future proposed streetcar lines in Kansas City. The first line, from downtown to midtown, is under construction and opens next year. For three future lines – from midtown to UMKC, along Linwood Boulevard east of midtown, along Independence Avenue east of the River Market – MoDOT would contribute $123.99 million, matched by $356 million from Kansas City.

• Acquiring the old Rock Island Line rail corridor from Pleasant Hill north to an area just west of the stadiums. Jackson County, hoping to start commuter rail some day, has worked out a deal to buy that from the Union Pacific. MoDOT would pay $24 million, and the county would pay $48 million. The county has applied for federal funding for that. With that corridor in hand, the state could extend the Katy Trail into the Kansas City area, regardless of what happens with commuter rail plans. Both the Katy and a commuter line could fit in the corridor, officials have said.

Missouri last raised taxes for highways in the 1990s by phasing in a motor fuel tax increase. A voter-approved measure shifted existing vehicle sales tax revenues to the highway agency about a decade ago. But this would mark the first time that a general sales tax has been imposed for transportation.

Opponents of the measure, including Gov. Jay Nixon, have said the sales tax would disproportionately hit the poor, who may spend a greater proportion of their income on consumer purchases.

Adolphus Pruitt, the president of the NAACP in St. Louis, told state transportation commissioners Wednesday that the tax wasn't fair and the project list should have been tilted more heavily to urban areas that generate the most tax revenues.

The biggest project on the list is the reconstruction and widening of 200 miles of Interstate 70 between the St. Louis and Kansas City areas. It would receive $500 million from the sales tax, with the rest of the $1.5 billion project paid for through existing revenue sources.

The Examiner’s Jeff Fox contributed to this article.