meet customer needs and put us in a position to handle demand changes . we will also continue utilizing industrial engineering techniques to improve productivity . 2022 fuel prices 2013 uncertainty about the economy makes fuel price projections difficult , and we could see volatile fuel prices during the year , as they are sensitive to global and u.s . domestic demand , refining capacity , geopolitical issues and events , weather conditions and other factors . to reduce the impact of fuel price on earnings , we will continue to seek recovery from our customers through our fuel surcharge programs and to expand our fuel conservation efforts . 2022 capital plan 2013 in 2010 , we plan to make total capital investments of approximately $ 2.5 billion , including expenditures for ptc , which may be revised if business conditions or new laws or regulations affect our ability to generate sufficient returns on these investments . see further discussion in this item 7 under liquidity and capital resources 2013 capital plan . 2022 positive train control ( ptc ) 2013 in response to a legislative mandate to implement ptc by the end of 2015 , we expect to spend approximately $ 200 million during 2010 on the development of ptc . we currently estimate that ptc will cost us approximately $ 1.4 billion to implement by the end of 2015 , in accordance with rules issued by the fra . this includes costs for installing the new system along our tracks , upgrading locomotives to work with the new system , and adding digital data communication equipment so all the parts of the system can communicate with each other . 2022 financial expectations 2013 we remain cautious about economic conditions but expect volume to increase from 2009 levels . in addition , we anticipate continued pricing opportunities and further productivity improvements . results of operations operating revenues millions of dollars 2009 2008 2007 % (  % ) change 2009 v 2008 % (  % ) change 2008 v 2007 .
what was the change in total revenue in millions from 2007 to 2008?
freight revenues are revenues generated by transporting freight or other materials from our six commodity groups . freight revenues vary with volume ( carloads ) and average revenue per car ( arc ) . changes in price , traffic mix and fuel surcharges drive arc . we provide some of our customers with contractual incentives for meeting or exceeding specified cumulative volumes or shipping to and from specific locations , which we record as a reduction to freight revenues based on the actual or projected future shipments . we recognize freight revenues on a percentage-of-completion basis as freight moves from origin to destination . we allocate freight revenues between reporting periods based on the relative transit time in each reporting period and recognize expenses as we incur them . other revenues include revenues earned by our subsidiaries , revenues from our commuter rail operations , and accessorial revenues , which we earn when customers retain equipment owned or controlled by us or when we perform additional services such as switching or storage . we recognize other revenues as we perform services or meet contractual obligations . freight revenues and volume levels for all six commodity groups decreased during 2009 , reflecting continued economic weakness . we experienced the largest volume declines in automotive and industrial .