A survey of 243 Perth businesses has found some are turning down work because traffic congestion in the metropolitan area is cutting into their profits and productivity.
According to the RAC BusinessWise survey some businesses have estimated having staff stuck in traffic is costing them as much as $100,000 each year.
The findings are consistent with research from BITRE that puts the cost of congestion in the WA economy at $1.1 billion a year.
Forty-seven per cent of businesses surveyed said they had changed the way their business ran because of congestion with many changing shift times for staff to start later and finish earlier.
Half the respondents to the survey said their business had experienced a loss in productivity.
Seventy per cent also believed congestion in the Perth's CBD had worsened over the last year.
According to the data more than half the businesses surveyed said they had no confidence that the government had adequate plans to tackle the congestion.
RAC head of member advocacy Matt Brown said that Perth's rapidly expanding economy and burgeoning population meant that without action the situation was only going to get worse.
"The survey shows that congestion is not just a social issue affecting commuters heading to and from work," Mr Brown said.
"Congestion is now a major economic threat to the continued prosperity of businesses in and around Perth.
"We need a long term strategy and significant investment if we are to deal with congestion in Perth before we end up with the gridlock which is associated with cities in the Eastern States."
According to the survey the congestion hot spots are:
1. Tonkin Highway, Leach Highway, Horrie Miller Drive
2. Kwinana Freeway, Leach Highway
3. Graeme Farmer Freeway, East Parade
4. Mitchell Freeway, Hutton Street
5. Mitchell Freeway, Hepburn Avenue
6. Wellington Street, William Street
7. Nicholson Road, Bannister Road
8. Kwinana Freeway, Beeliar Drive
9. Reid Highway, Malaga Drive
10. Great Eastern Highway, Roe Highway
