Tolls for road/bridge use

TLDR at end

Watched a video about roads, bridges and city gate tolls and fees for travelers during medieval times. Was super interesting from a historical aspect but have not had good luck implementing it into regular play.

I've been putting tolls at bridges and at gates for many years in my campaigns this as well as a sort of customs system that will charge for restricted items in certain parts of my world.

The problem I am having is players most of the time will use skills to intimidate, deceive or in some other way get out of the minimal cost of tolls. Sometimes even killing the "guards" at the bridge instead of paying.

I like to have situations like this in order to add some depth to the game if my players would take the time to delve into it.

Having in the past a small group of goblins charging tolls who's tribe had formed an alliance with the country's leaders and were responsible for maintaining the bridge and road through their territory while being allowed to keep a small stipend for themselves.

Players watched them charge a group of merchants with a half dozen guards with no altercation, then proceeded to kill them when asked for the regular fee.

In another campaign, the party used hold person and charm person to deal with human guards that were at a bridge collecting tolls.

I have yet to put a large monster like an ogre or troll at a bridge or other crossing because of the mobs low intelligence and ease at which my players could trick them.

Another example would be at city gates, where guards stop merchants and travelers to pay a small fee for entry, especially at a larger place where trade is important or there may be ordinance about weapons, magic or certain goods.

Players have on many occasions simply bypassed the gate altogether or used skills to intimidate or decive the guards only to get out of paying tolls.

As a result, a lot of what I would call 'bonus' content in the world in the form of quests, lore and other good opportunities for RP and adventure is simply bypassed, dismissed as boring or destroyed without a second thought as to what an encountered situation may actually be for in the campaign as a whole.

I have talked with my players in the several campaigns where this behavior has occurred to inform them that there is more going on than what they think and that they should explore opportunities they encounter with NPCs. It really hasn't changed the problem though.

Has anyone had a positive experience with adding tolls or guards to bridges or at city gates as a way to introduce content into their campaigns in a meaningful way that players engaged in as intended without having to drop constant hints, or do players all tend to see them as obstacles to overcome and bypass

TLDR. My players don't engage in encounters with tolls or guards at gates and bridges/crossroads even though they actually could add depth to lore and give extra quests for adventure/loot if they did. Has anyone had luck using these to add to their campaign?