Ambulances were obstructed by “reckless parking” on two separate callouts at beauty spots over the September weekend.
Emergency services experienced difficulty on their way to Rowardennan, on the eastern shore of Loch Lomond, on Saturday as they tried to help someone in trouble on Ben Lomond.
This was down to cars illegally parked along the side of the B837 road, which is a designated clearway.
The following day in Callander, a second ambulance was blocked by cars parked in front of an emergency access gate at Callander Crags. One car owner has been charged.
Drivers have been urged by authorities not to park along roadsides, block entrances and exits and to check ahead if somewhere is likely to be busy.
Simon Jones, director of conservation and visitor operations at the National Park, said: “These incidents and the many other examples of reckless parking on roadsides and crowded car parks this weekend highlight just how dangerous this behaviour is.
“It is extremely lucky that the outcome in both of these cases was not a lot worse, but it could be next time.
“While the National Park is there to be enjoyed, especially on a sunny holiday weekend, parking along the sides of already narrow or busy main roads and parking across exits, when car parks are full, could put lives at risk.
“This has been an ongoing issue in recent years and particularly since lockdown restrictions eased, so as partners we are working on longer term solutions such as further public transport, active travel options or parking capacity where appropriate.
“These are not quick fixes and will take time and we still need everyone to play their part by behaving responsibly and not making these problems worse.”
Following the incidents on Saturday, Police Scotland closed the B837 on Sunday morning to manage the high volume of traffic on East Loch Lomond. Officers also attended Callander Crags to move the obstructing vehicles.
Inspector Andy Bushell said: “There are designated parking areas within the National Park and if these are all in use then vehicles must seek other permitted parking zones and not leave cars on narrow access roads or public walkways.
“Recent incidents of inappropriate parking have resulted in emergency service vehicles being unable to pass and this is totally unacceptable.
“We regularly patrol the National Park and any obstructive or dangerous parking will be appropriately dealt with. This could include the physical removal of a vehicle, issuing drivers with a fixed penalty notice or even reporting individuals to the Procurator Fiscal.”
Overcrowding and irresponsible parking was also seen in several other areas around the National Park at the weekend, including at popular hills Ben A’an and Ben Venue in the Trossachs.
Stirling Council enforcement officers issued 145 parking tickets across the weekend at a number of locations.
Councillor Jim Thomson, convener of Stirling Council’s environment committee, said: “Some of the scenes in our rural areas last weekend were absolutely disgraceful, with irresponsible and illegal parking from a minority of visitors posing a serious risk to public safety.
“Our enforcement officers, who are working extremely hard across a large rural area to keep people safe in challenging circumstances, also suffered abuse from people visiting the area, which is completely unacceptable.”