You could plan a 1-way walk by walking the Trailway and getting the bus back - for example the X8 from Spetisbury or Sturminster Marshall to Blandford Forum, or the X10 between Blandford and Yeovil stops at Sturminster Newton and Shillingstone. The X3 from Blandford to Shaftesbury stops at the White Hart, Stourpaine. Click here to find bus times in Dorset.
Stour Meadow, Blandford DT11 9LS - FREE CAR PARK behind Hall & Woodhouse Brewery and TESCO - follow signs and tarmac paths across meadow to the black bridge over Stour - otters often seen in the area.
Milldown Milldown Road, Blandford DT11 7SN - FREE CAR PARK, there is a ramp down into the cutting onto the trackbed, then turn under the bridge to go north towards Stourpaine, or away from the bridge for a traffic free route into Blandford.
Fiddleford Manor English Heritage site (DT10 2BX off A357) has 30 FREE spaces close to the Trailway and the Manor is an amazing mediaeval building. From the car park turn left away from A357, turn right at farm and then turn left along Bridleway.
By Train? yes the railway has been closed since 1966 - but, if you want to plan a bike tour you can bring your bike to Poole Station and then use the N25 Sustrans route to Blandford, or you can get the train to Gillingham and use the Sustrans N253 route to Sturminster Newton.