"When flying VFR and receiving enroute traffic advisories (flight following), is there a way to get your routing information into the ATC system, so that it's available to the next controller?" - Mike S.
“First, you have to realize that the ATC system exists primarily to move and separate IFR traffic – VFR traffic is a secondary function. VFR flight plans filed with AFSS (Automated Flight Service Station) are not passed to ATC. They remain strictly within the AFSS network for search and rescue purposes only.
When you request VFR flight following outside the local approach control area, the controller will normally enter a mini-flight plan in the system. The only information that a mini plan contains is for handoff purposes. However, in busy and complex areas such as the Northeast, the mini-flight plan may not process through to the same sectors or facilities that an IFR flight plan would. This is because the routing is not the same as the IFR route. The data will go to the sector that normally gets the IFR data. And sometimes that’s why you don’t get a VFR handoff.
ATC does generally expect a VFR pilot to proceed direct to the destination rather than via airways, especially today where virtually everyone has GPS. If you will be navigating other than a direct course, advise ATC. For example a student pilot on a solo cross country will be navigating by pilotage, using landmarks, lakes, bridges, etc. Just let the controller know your intentions, but briefly. No need to tie up the frequency with every checkpoint.
You can request a VFR handoff but it is always subject to workload and equipment limitations.”