Disruption to the region's road and rails links caused by snow and flooding at the end of last year cost the South West more than £165 million according to a new report.
Over 350 businesses took part in the survey, by South West Chambers of Commerce (SWCC), in which businesses were asked to share their views on how the region's transport connectivity issues affect them.
The results will serve as the basis of a lobbying campaign for improved investment in South West transport infrastructure.
Some 65% of businesses claimed they had experienced difficulties with the closure of the rail and road links in the South West as a result of the flooding incidents and snow in November and December.
Two respondents stated the disruptions had cost their businesses more than £500,000. Based on the responses from all other participants and taking into account the 100,000 businesses trading in the South West, the results of the survey indicate the total cost to the region of the recent transport disruptions could be some £167 million.
Throughout the disruptions, many businesses felt that the South West was effectively cut off from the rest of the UK. Respondents detailed journeys from Exeter to London which took up to 10 hours and for one company, not a single employee was able to get to the office due to road disruptions.
Severe transport difficulties meant late or non-arrival of staff and clients; cancelled or postponed appointments and business trips; cancelled hotel bookings; a noticeable drop in customers for retail companies and resource issues for businesses relying on an inward supply of goods.
This resulted in lost revenue, loss of working days, reduced productivity, additional costs for alternative arrangements and significant adverse effects on new business and project delivery.
Statistics recently published by HM Treasury show that the average public sector spend for transport in 2010/11 was just £212 per person in the South West.
This is the lowest figure in the UK and just over a quarter of that spent per person in London, which amounted to £774 in the same period.
The Government also recently announced that the High Speed Rail Network programme would be extended to the North West and North East, with no mention of such plans for the South West.
Derek Phillips, chairman of South West Chambers of Commerce said: "Our message to Government is that the South West has received far less than its fair share of investment in transport infrastructure for far too long and it is time that this unacceptable situation ceases. We are specifically looking for electrification of the rail line south of Bristol into Cornwall, the dualling of the A303 and A30 along their entire lengths and much improved mobile and Wi-Fi connectivity along the arterial routes to the South West."
The survey also revealed that South West perceptions about the region's transport infrastructure are generally negative. Some 66% of respondents believed that investment in the South West's road infrastructure is poor or very poor; 65% felt the same about the region's rail investment.
Transport links to London and to destinations with major airports for international travel were of particular concern.
One respondent said: "I recently travelled from London to Manchester by train in less than two hours. After I had completed my business, I then went from Manchester to Plymouth by train; eight hours and two changes later I eventually arrived. This is not good for anyone but extremely discouraging for business users."
SWCC recently announced lobbying for improved investment in South West transport connectivity as its number one priority.
A quarter of the responding businesses secure more than 75% of their revenue from outside the South West, and a third of South West businesses use transport links to get to and from other parts of the UK on a daily basis, with a further third using it weekly.
David Parlby, chief executive of Plymouth Chamber and a member of SWCC, said the results of the survey consolidated SWCC's view that the South West has suffered from significant underinvestment for a prolonged period of time in comparison with other regions.
"On-going transport connectivity issues are more than just an inconvenience for the South West. The results of the survey show that businesses in the region are literally paying the price for the poor infrastructure and lack of investment," he said.
"This is a critical issue which impacts on South West businesses of all sizes and from all industries, every day. Appropriate levels of investment in our transport connectivity are fundamental to the region's future economic development and ability to attract new businesses and inward investment. However, we are currently missing out on transport investment opportunities and being omitted from national improvement programmes."
SWCC will now be undertaking additional in-depth analysis of the survey results to direct a strategy for a lobbying campaign which will aim to secure the investment and political support necessary for improvement.