According to one academic source:
The Supreme Court, however, has yet to review the constitutionality of curfews. They declined in 1976 to hear a case about juvenile curfews.
And in somewhat more detail, regarding lower courts' decisions:
Litigants challenging juvenile curfew laws generally have not argued that youth is a “suspect classification” like race or gender. Instead, the typical claim is that curfew laws single out
juveniles from the rest of the population in a way that infringes upon
their fundamental right of “free movement.” In response, state governments have argued that no such right exists and that curfews are, in
any event, justified by the compelling interests of preventing juvenile
crime and protecting juveniles from becoming victims of crime.[...]
Courts have tried to fit the problem of juvenile curfews into the
existing formal framework, with inconsistent results. They have
employed all three tiers of scrutiny: not only rational and strict,
but also intermediate scrutiny, which is not typically used to address
asserted infringements on fundamental rights. Intermediate scrutiny,
which evolved to deal with the problem of gender discrimination, permits a more fact-specific approach than strict and rational review and
enables a court to uphold or strike down legislation depending on how
the court weighs the various interests involved
The courts’ struggles have played out visibly in recent years.
Among the six federal appeals courts to rule on curfew challenges since 1993, two courts—the Fifth and Ninth Circuits—applied strict
scrutiny but reached opposite results. Four courts applied intermediate scrutiny with equally inconsistent results: The Second and
Seventh Circuits struck down the curfews before them, while the
Fourth and D.C. Circuits upheld curfew laws. The two most recent
state supreme courts to address juvenile curfew laws both applied
strict scrutiny but also reached opposite results. One commentator
went so far as to observe that, in juvenile curfew cases, “the level of
scrutiny applied has proven largely irrelevant.”
[...]
Although the Supreme Court has
held that the Constitution protects an individual’s right to interstate
travel, it has not decided whether individuals enjoy a right to
intrastate travel. In addition, it is debatable whether the “localized
movement” implicated by juvenile curfew laws fits within a general
right to intrastate travel or free movement. Another open question is
whether minors enjoy such a right at all. [footnote on that:] See Hutchins v. District of Columbia, 188 F.3d 531, 538 (D.C. Cir. 1999) (en banc)
(plurality opinion) (“[W]e must ask not whether Americans enjoy a general right of free
movement, but rather whatever are the scope and dimensions of such a right (if it exists),
do minors have such a substantive right?”).
[...]
In Qutb v. Strauss, the Fifth Circuit considered a Dallas, Texas
curfew ordinance that prohibited persons under the age of seventeen
from remaining in a public place from 11:00 p.m. until 6:00 a.m. on weeknights and from midnight until 6:00 a.m. on Friday and Saturday
nights. The curfew also contained a number of exceptions designed to
address concerns from earlier curfew cases.
The court began by invoking the formal tiers of scrutiny framework. Perhaps to avoid the difficult question of how the framework
might accommodate the peculiar “fundamental interest” in moving
about freely, the court “assume[d] without deciding” that the curfew
impinged upon a fundamental right and therefore subjected the ordinance to “strict scrutiny.” As an early sign that the strict scrutiny
standard might lack its traditional bite, however, the court noted that
the “ordinance is directed solely at the activities of juveniles and,
under certain circumstances, minors may be treated differently from
adults.”
The court had no trouble concluding that the city had a compelling interest in reducing juvenile crime and victimization. Instead,
the decision hinged on whether the curfew was narrowly tailored to
further those interests.
In support of the curfew’s tailoring, the city presented statistical
data to establish the following: (1) juvenile crime increases proportionally with age; (2) juveniles were arrested in Dallas for over five
thousand crimes per year, including murders and sex offenses; (3)
murders (including those committed by adults) were most likely to
occur between 10:00 p.m. and 1:00 a.m.; (4) most aggravated assaults
occurred between 1:00 a.m. and 3:00 a.m. and sixteen percent of rapes
occur on public streets; and (5) thirty-one percent of robberies occur
on streets and highways.71
The court concluded on the basis of these statistics that the city of
Dallas had established a sufficient “fit” between the curfew ordinance
and the city’s compelling interests.72 The court also concluded that,
because the curfew contained numerous exceptions, the ordinance
“employ[ed] the least restrictive means of accomplishing its goals.”
(The author of the paper disagrees with courts' findings and spends some paragraphs attacking them [in particular the interpretation of the statistics], but I'll skip that there... simply because another court judging a fairly similar matter found otherwise:)
In Nunez v. City of San Diego,
the Ninth Circuit considered a
challenge to a substantially more burdensome curfew than that upheld
by the Qutb court. No hours extension was provided for weekend
nights, and the curfew lacked many of the exceptions that had characterized the Dallas curfew.
Unlike the Fifth Circuit in Qutb, the Nunez court expressly recognized the “right to free movement” as a fundamental right. Following the formal binary approach for fundamental interests, the
court therefore applied “strict scrutiny.” Nevertheless, the court
determined that in applying strict scrutiny it would recognize that
“minors’ rights are not coextensive with the rights of adults,” not
because minors lack such rights or because their rights are not as “fundamental,” but because “the state has a greater range of interests that
justify the infringement of minors’ rights.” In applying its chosen
standard of review, the court announced that it would be “mindful
that strict scrutiny in the context of minors may allow greater burdens
on minors than would be permissible on adults as a result of the
unique interests implicated in regulating minors.”
Finding that reducing juvenile crime and victimization is a compelling interest, the Nunez court turned to means testing. The city
presented national data showing, at best, lukewarm support for the
curfew’s efficacy. The data revealed that (1) the juvenile crime rate
was rising nationally, and that (2) juvenile crime nationally peaks at
3:00 p.m. and again at 6:00 p.m. Localized statistics also provided
mixed support: A 1995 report showed that only fifteen percent of
juvenile arrests took place during curfew hours, and that juvenile victimization actually increased during curfew hours in the year after
enforcement began.
The court determined that while “the statistical evidence provides
some, but not overwhelming, support for the proposition that a curfew
will help reduce crime,” the city had made “little showing . . . that the
nocturnal, juvenile curfew is a particularly effective means of
achieving that reduction.” The court also “reject[ed] the City’s further justification that the ordinance ha[d] the additional beneficial
deterrent effect of permitting police officers to get juveniles off the
streets before crimes are committed.”
The court’s response to the evidence, however, was striking. In
spite of its apparent rejection of the city’s justification for the curfew
ordinance, the court ruled that in the face of such “concerns” the ordinance might nevertheless survive strict scrutiny. After concluding
that minors are especially vulnerable at night—a position unsupported by the city’s own statistics—the court opined that San Diego
had established “some nexus” between the curfew and its compelling
interests. [...] The court
struck down the curfew only because it lacked the exceptions from the Dallas curfew upheld in Qutb.
[...]
Schleifer involved a curfew similar to the Dallas curfew from
Qutb. In an unusual step, the court began by considering what level
of scrutiny should apply to children’s rights without ever mentioning
which rights were implicated. While acknowledging that laws that
impinge on a group’s fundamental rights are subject to strict scrutiny,
the court nevertheless reasoned, based on some of the Supreme
Court’s juvenile rights decisions, that minors’ rights are not coextensive with those of adults. The court therefore concluded that intermediate scrutiny, not strict scrutiny, was appropriate.
The Hutchins opinion followed a similar pattern. Addressing
another Dallas-model curfew, the D.C. Circuit, sitting en banc, splintered, revealing the tenuousness of the tiers of scrutiny framework as
applied to juvenile curfew laws. A plurality of four judges reasoned
that minors do not enjoy a fundamental right “to be on the streets at
night without adult supervision,” and therefore would have applied a
rational basis test. Three judges concluded for reasons substantially
expressed in Schleifer that intermediate scrutiny was appropriate, and
that the curfew should be upheld.
Regarding the (fairly well-known) distinction that US Supreme court applied to minors' rights, but which nonetheless is/was open to further interpretation(s):
In Bellotti,
the [US Supreme] Court approved parental-notification provisions in abortion statutes as long as the statutes contained judicial bypass procedures. In
its opinion, the plurality “recognized three reasons justifying the conclusion that the constitutional rights of children cannot be equated
with those of adults: the peculiar vulnerability of children; their
inability to make critical decisions in an informed, mature manner;
and the importance of the parental role in child rearing.”
Courts that invoke Bellotti in the juvenile curfew context often
have read this language to establish a test under which children enjoy
lesser rights if at least one of the three prongs—vulnerability, inability
to make mature decisions, and the importance of the parental role—
are implicated by the circumstances in question. Courts have, however, disagreed on the ramifications of this test. In Nunez, for
example, the Ninth Circuit concluded that “[t]he Bellotti test does not
establish a lower level of scrutiny for the constitutional rights of
minors in the context of a juvenile curfew. Rather, the Bellotti framework enables courts to determine whether the state has a compelling
interest justifying greater restrictions on minors than on adults.” In
contrast, the D.C. Circuit concluded in Hutchins that Bellotti “necessarily” means that intermediate scrutiny is the proper test.
(Emphasis in original.)