TORONTO -- Ontario's auditor general says the Liberal government is doing a poor job of overseeing contractors for road maintenance and public transit projects, spending millions of dollars to repair their shoddy work, including part of one bridge that was installed upside down.

Auditor general Bonnie Lysyk also blasts Metrolinx for weak management of public transit contracts, warns of serious shortcomings in the health-care system, and predicts cap-and-trade will cost businesses and individuals $8 billion between 2017 and 2020.

In her annual report, Lysyk says the pavement on some Ontario roads and highways that is supposed to last 10 to 15 years starts to crack after just two or three, significantly increasing the Ministry of Transportation's repair costs.

"For a sample of five highway jobs...we calculated that the ministry paid $23 million for repairs after one one-to-three years, on top of the $143 million to initially pave these highways that should have lasted 15 years," reported Lysyk.

She said the ministry has known about problems with premature cracking since 2000, but still agreed to a request from asphalt producers and cement suppliers to delay plans to start tests that would identify asphalt that is likely to start breaking up before it should.

The auditor found contractors were "tampering with asphalt samples" so they could obtain part of the $8.8 million the ministry paid in bonuses for them to include the quality asphalt specified in the contract, which they "are always expected to do anyway."

The province spent about $6.1 billion on 2,100 highway projects in the past five years, with $1.4 billion of that going to road paving, but the auditor found the Ministry of Transportation allowed the Ontario Road Builders' Association "to influence its internal operational policies to benefit contractors rather than the ministry."

Contractors, not the province, hire the engineers who certify the quality of construction projects, and the ministry allows contractors who received unsatisfactory ratings to win new contracts for "significant amounts of work," even though they were supposed to be prevented from bidding.

Lysyk said Metrolinx does not hold contractors and design consultants accountable for public transit projects that are late or inadequate, and like the ministry of transportation, sometimes awards new work to contractors that performed poorly in the past.

"The lack of a process to hold construction contractors accountable contributes to projects being completed late, inconveniences commuters and adds extra costs for Metrolinx and taxpayers," said Lysyk. "Metrolinx should introduce penalties such as late fines."

Metrolinx is now responsible for $1 in every $7 dollars of government capital spending, but the auditor found the transit agency often doesn't know if it's getting what it pays for.

CN admitted it charged GO Transit, which is administered by Metrolinx, for new rail when it actually sold the provincial agency recycled rail.

"When it pays for new parts it does not check to ensure that the parts are new," said Lysyk.

One contractor working on a pedestrian bridge over Highway 401 in Pickering was so bad Metrolinx staff had to take over many of its duties, but the agency then hired the same contractor which caused significant damage to the bridge in phase two.

The contractor then installed one of the bridge trusses upside down, and even though Metrolinx had to fix it and take over almost all of the other contractors' responsibilities, the company was still paid the full $19 million.

Lysyk's report also takes the Liberals to task for growing waiting lists in emergency rooms, and said wait times for elective surgeries at Ontario's largest hospitals have not improved in five years, but surgical suites are not being fully utilized.

"Many hospitals are closing most of them on evenings, weekends, statutory holidays, March break and for two to 10 weeks during the summer," she said.

The auditor also found the Ministry of Health does not investigate inappropriate or anomalous billings by doctors even though it allocates $11.6 billion for physician compensation each year. Nine specialists claimed to work over 360 days in fiscal 2015/16, with six of them billing for the full 366 days.

"Since the beginning of 2013, the ministry has nor proactively pursued recovery of overpayments," said Lysyk.

The auditor said the province often ends up paying twice for the same patient when someone who signed up with a Family Health Team visits a walk-in clinic.

Lysyk was very critical of the province's services for children and adults with mental health issues.

"Despite a 50-per-cent increase in hospitalization of children and youth with mental health problems since 2008/09, the province has not analyzed the reasons for the increase or taken steps to address it," she said.

The report also notes that Ontario's health-care sector has spent $8 billion over the last 14 years to implement electronic health records but still hasn't created them for everyone.