Short answer. Yes. Article 1751 says the fact that the carrier had no competitor along the route shall be taken into consideration in deciding whether a stipulation limiting its liability is reasonable, just and in consonance with public policy. A carrier that was the only option makes a low limit harder to defend, not easier.
What the law says
The fact that the common carrier has no competitor along the line or route, or a part thereof, to which the contract refers shall be taken into consideration
Civil Code, Article 1751 — No Competition Considered. Read the full provision →
The rule
Article 1751 does not decide whether a liability limit is valid; it adds one factor to the balance. It provides that the fact that the common carrier has no competitor along the line or route, or a part thereof, to which the contract refers shall be taken into consideration on the question of whether or not a stipulation limiting the common carrier's liability is reasonable, just and in consonance with public policy. So the absence of competition is not a separate ground for striking a clause down, but it is relevant evidence, and the law directs that it be weighed.
Why a monopoly cuts against the limit
The reason a lack of competition matters goes back to consent. A limit on liability is defensible partly because the shipper could have gone elsewhere and chose this carrier and its terms. Where the carrier is the only one serving the route, that choice is illusory: the shipper either accepts the limit or does not ship at all. In that setting a clause the carrier drafted in its own favour deserves harder scrutiny, because the shipper's agreement to it was not the product of a real market choice.
One factor among several
It helps to see where this fits. Whether a limitation is reasonable and just, and was fairly and freely agreed, is the main question the Code poses. The no-competition fact feeds into that question rather than replacing it: a limit can still be upheld on a monopoly route if the sum is fair and the shipper genuinely had the option of declaring a higher value, and a limit can still fall on a competitive route if the amount is absurdly low. Competition is one input the court must consider, weighed together with the size of the limit and the way the shipper came to accept it.
What this means when you challenge a limit
If you are a shipper facing a limitation you think is unfair, the route matters as evidence. Establish whether the carrier was the only one you could realistically have used for that shipment, whether the terms were dictated rather than negotiated, and whether you were ever offered the chance to pay more for fuller cover. Set that against the size of the limit and the value of the goods. The carrier will want to show the opposite: a market with alternatives and a shipper who chose the cheaper terms knowingly. The documents showing how the deal was struck are what decide it.