It's either a once-in-a-generation opportunity to transform the city or a disastrous waste of money that will cripple London for the next decade or more.

Three of London's four mayoral front-runners have said they oppose the $500 million bus rapid transit plan. But what do they offer as an alternative to the city's transit woes?

BRT Basics $500 million plan to run bus rapid transit along two L-shaped corridors spanning about 24 km

The province has committed $170 million for the project

The federal government has committed to $204 million for transit infrastructure, not specifically BRT

The city has said it will pay up to $130 million

The city portion will be funded mostly through development charges, not property taxes

The BRT plan includes express buses in dedicated lanes, but also upgrades to routes, wifi and charging stations at bus stops and smart technology that will synchronize traffic signals around the system. 35 new stops and dedicated lanes will ease congestion for other vehicle traffic, BRT officials say.

The provincial cash that's been promised is tied to the business case for the project. If there are significant changes to the council-approved BRT design, a new business case would have to be submitted. To be considered for federal funding, the province has to submit project proposals by September 30.

Here's what the mayoral front-runners have in mind for transit:

Paul Cheng

Mayoral candidate Paul Cheng. (Mark Spowart/Special to CBC News)

Cheng's plan, to be released Friday, relies on upgrading many bus stops to bus bays.

"If we move the buses off the roads, that will free up the roads for the cars."

Parts of the city, such as Oxford and Wharncliffe, Huron and Highbury or Wonderland and Village Green, cry out for bus bays, he said.

"There's tons of space for the buses. Right now, when a bus stops, the whole of Wonderland stops. Why not move the buses off to one side, that will allow the vehicles to go through."

Drivers will need to be taught to be more willing to yield to buses merging back from the bus bays, he said.

Fix pot holes and unify bike lanes for cyclists.

Cheng said the bus bays should be upgraded within a year to a year-and-a half of his becoming mayor.

Ed Holder

Mayoral candidate Ed Holder. (Mark Spowart/Special to CBC News)

Holder says he wants more efficient bus service to industrial east and south parts of London.

We have an industrial east and industrial south that either don't have bus service at all or at best, poor timing associated with it."

Those gaps in service limit the applicant pool for employers, Holder said.

He wants to survey businesses where there's no bus service, or poor bus service, about what service upgrades would be required so buses are synchronized with shift changes.

Holder wants to partner with private companies to have them build bus bays for their employees. "There's a willingness for businesses to cooperate."

Synchronize lights for better traffic flow.

For cyclists, Holder would improve "sharrows," those arrows that remind drivers to share the road, and for pedestrians he would make sure sidewalks are wide enough and smooth.

Paul Paolatto

Mayoral candidate Paul Paolatto. (Mark Spowart/Special to CBC News)

Paolatto says he wants to "introduce new features and technologies, improve the value of the system, build ridership, build revenue, and then allow that revenue to pay for more upgrades."

"We need to grow with demand, not in hopes of it," he said.

His first priority would be to move the CP tracks which cut off traffic on Adelaide and on Richmond. Despite a report to city council in May that said CP refused to contribute to the cost of even a feasibility study to move its tracks, Paolatto says he still thinks "there's a deal to be had there."

Failing that, he would build additional overpasses and underpasses as needed.

Paolatto's plan is the most robust, spanning several blog posts. He would install more right turn lanes and advanced greens to improve traffic flow, expand roads in strategic spots, expand bus bays, synchronize traffic lights and give traffic signal priority to pedestrians, cyclists and transit "as the market requires."

He would put in parking lots at the city's entrance points to encourage ride sharing and introduce peak-period traffic flow rules, such as limiting left turns on major roads during rush hour.

For cyclists and pedestrians, Paolatto commits to fixing and maintaining year-round bike and walking paths. He plans to add $10 million to London's $20 million active transportation budget.

Paolatto's plan adds $225 million to the capital budget and $2 million to the operating budget to build and maintain traffic light synchronization, peak traffic management systems and high occupancy vehicle lanes.

Tanya Park

Mayoral candidate Tanya Park. (Mark Spowart/Special to CBC News)