Australia's top motorists' lobby is demanding state and federal governments publish their cache of road data to stamp out pork-barrelling and control the spiking road toll.
Australian Automotive Association managing director Michael Bradley said the states had previously promised transparency but hadn't delivered.
"Every state and territory government has promised to report the road safety data they collect, but so far none have," Mr Bradley said.
The federal, state and territory governments are negotiating a new National Partnership Agreement that will determine road funding for the next five years, so any transparency promise must be written into the new agreement, he said.
Mr Bradley said the issue should be of particular interest to the south-west, which hosts some of the worst roads in the country. "You just need to look at the Princes Highway, which is a terrible road all the way from Wollongong," he said.
The most important road condition data comes from the Australian Road Assessment Program, or AusRAP.
"AusRAP collects 22 different data points every 200 metres along a given road, with everything from the road surface, lines, barriers, whether it has rumble strips, and at the end it spits out a star rating which essentially tells you how likely you are to be injured driving along that road," Mr Bradley said.
Wannon Liberal MP Dan Tehan obtained the AusRAP data for the region under Freedom of Information laws, and it revealed a dozen major arterial roads received the lowest possible one-star rating.
But Mr Bradley said the data didn't simply indicate how dangerous a section of road was, it also showed what type of improvement would most efficiently make it safer.
"So it also tells you if you've got $1 to spend then this is the best way to spend it if you want to save a life," he said.
"We want that data released because you'll be able to tell whether the money is going where it needs to go."
Mr Bradley said road funding was uniquely rort-able in the federal landscape, because unlike the funding for things like education or health, it was handed over to the states with no strings attached.
"For every other department, that funding has to be justified, but not for transport," he said.
"When you ask voters about that they're deeply cynical, they say it's because road funding is allocated to win seats, not to save lives."
Crash data was another trove of information he said urgently needed publishing. "Some states, like Victoria, already put some data up, but it's invariably outdated or it's too broad to be useful. They need to publish the up-to-date data in full."
Mr Bradley said information like crash speeds, weather conditions, and licence and vehicle types were all hugely valuable details for the public to have.
"Then the third category is enforcement data, so that's assessing the effectiveness of police interventions like random breath testing, speed cameras, seatbelt management and other campaigns," he said.
"The strange thing is, every state has wildly different approaches to this stuff. It can't all be 'best practice' so if it's all kept hidden, how can we work out what the best approach is?"
He said transparency could only improve outcomes. "And it's clear the current approach isn't working, our road toll is rising when it should be going down," he said.
"This is a problem that is going to hospitalise 100 people today and another 100 tomorrow."
"We're simply saying we've got a one in five-year chance to do this. They're currently negotiating an agreement that will determine how $50 billion is spent and at the moment it's a blank cheque, no strings attached.
"They need to make that funding contingent on publishing the data."
Mr Bradley said every National, Liberal, Greens and independent federal MP had signed on to support the push. He said Mr Tehan had been the first to sign on.
"To their credit, (Transport Minister) Catherine King and Anthony Albanese ran for election pledging transparency in government," Mr Bradley said.
"Now they need to show they were serious about that pledge."