Proponents of the transportation package known as Measure R say its impact would be transformative in traffic-plagued Los Angeles County. Its half-cent sales tax increase, if approved, would begin the so-called Subway to the Sea, get the Green Line light rail to Los Angeles International Airport, widen the 5 Freeway at the bottleneck before the Orange County line and add carpool lanes.
Opponents see a far different picture: a spending plan that shovels too much money into the subway and doesn't return enough sales tax revenue to other parts of the county.
Here's a look at some of the basics of what will be the third transportation sales tax proposal to face voters in the last 28 years:
How much would Measure R raise?
Proponents say $30 billion to $40 billion, but it depends on how much sales tax revenues grow over the 30-year life of the Measure R tax hike. The two prior sales tax increases, in 1980 and 1990, each raised about $686 million in 2007.
What would Measure R finance?
The accompanying chart is a partial list of projects. The subway extension potentially gets the most money. The sales tax also would freeze regular Metropolitan Transportation Authority fares until 2010 and fares for seniors, the disabled, students and those on Medicare until 2013.
And what would the sales tax rate be in L.A. County if Measure R passes?
The new rate would be 8.75%. In California, only Alameda County has a rate that high, although there are a few cities that are even higher.
The sales tax hike would add $5 to an item that costs $1,000 and $100 to the price of a $20,000 purchase.
Would Measure R raise enough money to finish all the projects it proposes to build?
Probably not. Most of the projects will need more money to be completed. The list of Measure R projects is long because it was designed to secure political support by offering something for many constituencies.
It also should be noted that many of the projects, such as the subway, have yet to receive environmental clearances that would allow them to start construction.
So how far does $4.1 billion get the subway?
The MTA says that could be enough to extend the line from its terminus at Wilshire Boulevard and Western Avenue to Westwood. The route hasn't been decided, but a recent MTA study recommended that the subway follow Wilshire to Beverly Hills, swing south to Century City and then north to Westwood.
What about the second subway that the MTA wants to build from Hollywood to Beverly Hills?
The agency's staff has said that the Wilshire route should be built first. There is no money in Measure R for the second line.
Does the 1998 ballot measure approved by voters that prohibits sales tax money from being used for subway tunneling apply to Measure R?
No. The 1998 ban remains in effect, but applies only to the 1980 and 1990 sales tax increases. Measure R, in effect, creates a new pot of money and one of the co-writers of the 1998 ban, county Supervisor Zev Yaroslavsky, supports Measure R and the subway addition.
Can the MTA board change the spending plan?
Yes. State law would have to be changed to divert the minimum amount of funds guaranteed for projects such as the subway, Expo Line and Gold Line Foothill extension, according to the MTA.
A supermajority of MTA board members could vote to move money between other projects, with some restrictions.
Can the Legislature raid Measure R funds?
No. The money would belong to Los Angeles County. The Legislature can, however, continue to keep gasoline sales tax money that Sacramento is supposed to send back to counties.
Who is for and against Measure R?
There is a healthy list of elected officials on both sides of the issue. Editorials among daily newspapers have varied -- The Times, the Daily News, the Daily Breeze and La Opinion are for Measure R and the Press-Telegram, the San Gabriel Valley Tribune and the Antelope Valley Press are against, to name a few.
The Los Angeles County Federation of Labor and the Los Angeles Area Chamber of Commerce support it.
Among prominent politicians, Los Angeles Mayor Antonio Villaraigosa, county Supervisor Zev Yaroslavsky and Assemblyman Mike Feuer (D-Los Angeles) have been the most vocal proponents.
Supervisors Mike Antonovich, Don Knabe and Gloria Molina have been fighting the measure, saying the MTA's spending plan favors the Westside and denies other parts of the county their fair share of sales tax revenues.
The MTA and Measure R supporters rebut that, pointing to a variety of projects that would be built in different parts of the county.
If Measure R doesn't pass, how much money does the MTA have for new projects?
Both sides agree that hardly any big projects would be completed because of a shortage of local, state and federal money for transportation.
MTA chief Roger Snoble said that if Measure R fails, the only mass transit projects that will be completed in the near future are the first phase of the Expo Line light rail from downtown to Culver City and perhaps the Canoga Avenue busway.
"I think we all need to look at a Plan B and get something [another financing plan] out there quickly," said John Fasana, an MTA board member who is opposed to Measure R because he believes it doesn't provide enough assurances that the money would be spent as planned.
He believes that if Measure R fails, leaders from across the county could quickly reconvene and come up with a plan that they could take to voters as early as next year if a special election is called to deal with the state's multibillion-dollar budget shortfall.
Feuer said he thinks this election offers the best opportunity to pass Measure R because the presidential election will probably bring many people to the polls who are also sympathetic to mass transit.
"This electorate is unique and particularly well-informed," Feuer said. "And it's these new voters who are interested in taking much of the transit that would be built by Measure R."