In US rental car terms and conditions, what exactly is a "regularly maintained road?"

One of the comments nailed it: "they mean don't take our rental car to Burning Man.” - Eric Lippert

And Burning Man is easy - flat, hard, no chance of off-roading damage. People still pay. Note how in the link, some rental agencies play them for suckers, and they can - words are nothing, rental car contracts are clear, and only paper matters.

Paved roads only, is what Hertz's vehicle guide says, fine print end of line 1. The exact language is "Use of rental vehicles off paved roads is prohibited". It's not an or with "regularly maintained roads", it's an and.

This is a legal maneuver, mainly about a liability shift. This is fairly routine in EULA-style contract law, to stack the deck in their favor. Courts will support it if it's not unreasonable or unfair.

They make it a breach of contract to exit paved roads. They know you probably will drive it on unpaved driveways and maybe roads. Your argument is "it's a perfectly harmless gravel driveway". Their argument is "if it's so harmless, how'd you manage to break the car?" The point is to utterly deflate any argument you could possibly make.

Why don't they say "driving on unpaved roads is at your own risk"? Because they've litigated a lot of these, and they found that language doesn't work and raises the cost of litigation. Making it a violation of ToS makes it clear-cut.

Remember, the TOS only has effect if you damage the car or get it extraordinarily dirty. And even then, you have the recourse to argue that the gravel road was an entirely properly groomed highway in good order and the accident had nothing to do with the road. When the facts plainly show that, they are unlikely to invoke the TOS rule, not least because it would not be conscionable to do so and courts would spank them if they did. That saves you from unfair misapplication of the rule.

They want an airtight case if you "rack up the car" by driving where it doesn't belong. The TOS as written does that.

You need to find the actual rental terms because only that is legally binding. The ones I found are clear on the definitions:

Hertz

NEITHER YOU NOR ANY AUTHORIZED OPERATOR MAY... ENGAGE IN ANY WILLFUL OR WANTON MISCONDUCT, WHICH, AMONG OTHER THINGS, MAY INCLUDE RECKLESS CONDUCT SUCH AS: ... USE OFF PAVED ROADS OR ON ROADS WHICH ARE NOT REGULARLY MAINTAINED...

National

(10) Vehicle shall not be driven on an unpaved road or off-road.

Budget

It is a violation of this paragraph if: a. You use or permit the car to be used: ... or on unpaved roads

Avis

It is a violation of this paragraph if: a. You use or permit the car to be used: ... or on unpaved roads

Based on these terms you cannot drive on any of the roads you mentioned because they are unpaved.

This is a really broad question and the correct answer may actually depend on the regulations of a respective state for road maintenance. So I will try to answer this with references.

If you use the US Forest Service as an example, it has 5 road maintenance levels.

Road Maintenance Level 5

Assigned to roads that provide a high degree of user comfort and convenience. These roads are normally double-lane, paved facilities. Some may be aggregate surfaced and dust abated. The appropriate traffic management strategy is “encourage.”

Road Maintenance Level 4

Assigned to roads that provide a moderate degree of user comfort and convenience at moderate travel speeds. Most roads are double lane and aggregate surfaced. However, some roads may be single lane. Some roads may be paved and/or dust abated. The most appropriate traffic management strategy is “encourage.” However, the “prohibit” strategy may apply to specific classes of vehicles or users at certain times.

Road Maintenance Level 3

Assigned to roads open and maintained for travel by prudent drivers in a standard passenger car. User comfort and convenience are low priorities. Roads in this maintenance level are typically low speed, single lane with turnouts, and spot surfacing. Some roads may be fully surfaced with either native or processed material. Appropriate traffic management strategies are either “encourage” or “accept.” “Discourage” or “prohibit” strategies may be employed for certain classes of vehicles or users.

Road Maintenance Level 2

Assigned to roads open for use by high-clearance vehicles. Passenger car traffic is not a consideration. Traffic is normally minor, usually consisting of one or a combination of administrative, permitted, dispersed recreation, or other specialized uses. Log haul may occur at this level. Appropriate traffic management strategies are either to (1) discourage or prohibit passenger cars or (2) accept or discourage high-clearance vehicles.

Road Management Level 1

Assigned to intermittent service roads during the time they are closed to vehicular traffic. The closure period must exceed 1 year. Basic custodial maintenance is performed to keep damage to adjacent resources to an acceptable level and to perpetuate the road to facilitate future management activities. Emphasis is normally given to maintaining drainage facilities and runoff patterns. Planned road deterioration may occur at this level. Appropriate traffic management strategies are “prohibit” and “eliminate.”

Roads receiving level 1 maintenance may be of any type, class or construction standard, and may be managed at any other maintenance level during the time they are open for traffic. However, while being maintained at level 1, they are closed to vehicular traffic, but may be open and suitable for nonmotorized uses

All of the attributes of the roads which fall under each level of maintenance and some example pictures can be found at Guideliness for Road Maintenance Levels

From this document, it does seem that even Roads which fall under Level 2 Maintenance are considered "maintained" BUT I would never rent a Toyota Camry and take it out on such roads; as it would only be logical to traverse such roads on a high-rise vehicle. There may even be road signs specifying what kind of traffic may proceed beyond a specific point (indicating the start of a Level 2 maint. road).

Another deduction may be that if you are on a level 1 maintenance road while it is closed you may be in breach of the TOS. (Although you might never be able to access it on car while it's closed).

I am not sure about private roads; whether states regulate the owners for maintenance or not, that is something specific to a locality and it would be best if you contact the local DMV for such questions. e.g. people have quarter/half mile long driveways in rural areas, what category would they fall in and what consequences would be for a car breaking down on them would be specific to the local law.

In general, this is just one aspect of the TOS the rental companies use to safeguard their litigation interests. Even in the statement that you quoted:

Generally, Hertz vehicles, including 4-wheel drives, are to be operated only on regularly maintained roads. Off-road use is a violation of the rental agreement.

covers two aspects of driving. One that the vehicle is to be operated on a maintained road. The definition of a maintained road in a certain area/jurisdiction will define where you can take the vehicle. Two Off-road is a violation. Now, in complete technical terms, off-road would mean where there is absolutely no road i.e. driving over sand dunes, through a creek etc. Are gravel/unpaved/dirt tracks etc considered off-road for the TOS? that's something you would need a lawyer for :-p

But all in all, such statements are a part of almost any TOS be it car rental, software, appliances, toys almost everything. The sole reason is to safeguard the company's interests in case of any legal action by a customer.

Furthermore, you would know that you are a safe driver and not have to worry about the TOS in such details. It's not like the rental company would actually track and record where you took the car to use the TOS against you e.g. you are returning the car and the person goes like just a minute sir you took the car to X area and breached the TOS you need to pay $$ amount or face legal action; that would be absurd. However, if you bring the bar back in a damaged condition etc then they would use each and every clause in the TOS and whatever else documents you signed to keep them on the safe side in legal aspects.

According to a quick google search, this includes maintained dirt roads. In Hawaii, there are notifications of which dirt roads are not allowed to be driven on by rentals as well.

IANAL: Many people do not seem to be aware of this clause and have driven it on dirt roads (national parks) anyways with little issues. It has also been noted here that the policy may be due to a past where dirt roads held a greater liability than they do now and it may unfairly blanket all.

Use the vehicle smartly. If in doubt, check with the national parks and tourist guides. It seems there are pre-defined roads in which you cannot travel on with a rental. It may be wise to contact the customer service and tell them of the locations you plan to travel and to clarify if this would be acceptable or not.

Ultimately though from reading around, it seems most people are not aware of this clause and have taken rentals on regularly traveled dirt roads. I do not think this would be wise without consulting the company first. You may need to find an alternative means as a last resort (rental car for the hotel and city travel, uber for dirt roads/parks). It may also be best to see if you can contact people who have traveled and rented to the areas you want to go to and find out what they did.

I want to make it explicitly clear though I am not condoning the act of disregarding a policy. Merely reporting the fact that many have driven rentals on safe dirt roads in the past but due to the fact they were not aware that such a policy existed prior to posting their experience online. As with all things, the internet is never a place to seek consultation about policies and law. Best way to know for sure is to contact the company directly or find out from trip advisors in the area as stated above.

One class I don't see listed above is Seasonal Maintenance, where they are not maintained during winter months. A sign is placed at the point where the status changes and could be in the midpoint of a road. There are in some rare cases houses along these roads but the municipality that the road lies within determines if they will spend money clearing the road of snow in the winter or how soon after winter spring flood damage will be repaired. The seasonal maintenance has nothing to do with if the road is paved or not and I've been on a few that would have been smoother as dirt roads.

This is a kind of addendum to user71659's answer

In his question, gerrit asked:

None of those roads are paved ... How would I know whether those specific roads count as regularly maintained roads in the terms and conditions of car rental companies?

In the case of Hertz, you don't need to know. Their terms say you can't take their vehicles on unpaved roads.

You also can't take their vehicles on paved roads that are not regularly maintained but that's not what your question asks about.

See Vehicle Damage Due To Poor Road Conditions: Who Is Liable?

The legal interpretation of "regularly maintained" is likely to be in terms of the obligations of a city, county or state government (or other owner) to promptly fill in any reported pothole or rectify other "poor conditions" that are reported to them.

This question only has relevance if the car is damaged and stuck on the unpaved road. Wear to the shock absorbers etc. is basically impossible to measure and could easily be due to driveways, curbs etc. anyway.

I have rented from Hertz many times while staying with a close friend who lives off an unpaved road in Michigan, and I've never heard a peep from them after returning the vehicle despite having driven the unpaved road dozens of times during the rental period.