See introduction for a discussion of the provenance, dating and significance of the map displayed here and other maps in the collection that have been put on line. Email for a GPX file of the route that can be imported to various mapping programs (I can’t work out how to add it to WordPress).
The way from Preston passing Lea Hall to the north and on to Clifton is only roughly indicated on the map below. At the time the surveyors were working, the route swung towards the north bank of the Ribble crossing the Lea and Clifton marshes, the property of the Hoghton and Clifton families who both exacted tolls from travellers. The Hoghtons collected theirs on Lea Marsh at a place called ‘the stakes’, which is indicated on the map below.
The various routes between Preston and Clifton and on into the Fylde was treated in great detail by the former Lancashire county archivist R. Sharpe France.  The route shown on the second map below is that suggested by Sharpe France.
 R. Sharpe France, ‘The Highway from Preston into the Fylde’, The Historic Society of Lancashire and Cheshire 97 (1945): 27–58, https://www.hslc.org.uk/wp-content/uploads/2017/06/97-3-France.pdf.