The developer successfully opposed such a requirement, relying on this court's decision in City & County of Denver v. Denver Buick, Inc., 141 Colo. 121, 347 P.2d 919 (1959) (holding that a zoning ordinance requiring landowners to provide off-street parking was per se unconstitutional as a taking of property without just compensation). Several years after the YCC was built, this court overruled Denver Buick in Stroud v. City of Aspen, 188 Colo. 1, 6, 532 P.2d 720, 722–23 (1975) (holding that off-street parking requirements are not per se unconstitutional as a taking of property without just compensation; such requirements should receive the same consideration as zoning ordinances, which are “constitutionally permissible so long as [they are] not arbitrary and [are] reasonably related to the public safety, morals and welfare”). ¶ 6 The YCC has designated a common area for on-site parking along the front of its property that is large enough to allow up to forty-three cars to park perpendicular to the buildings.

The prohibition against retrospective laws at the state level applies equally to local government. City County of Denver v. Denver Buick, Inc., 141 Colo. 121, 140, 347 P.2d 919, 930 (1959), overruled on other grounds by Stroud v. City of Aspen, 188 Colo. 1, 532 P.2d 720 (1975). The application of a constitutional standard is a question of law which we review de novo.

The provisions of this chapter and any amendments hereto shall not affect the review of any . . . building permit application lawfully submitted prior to the effective date of this chapter pursuant to the provisions of the zoning . . . regulations in effect immediately prior to the effective date of this chapter. Marshall cites our decision in City and County of Denver v. Denver Buick, Inc., 141 Colo. 121, 347 P.2d 919 (1960), overruled on other grounds, Stroud v. City of Aspen, 188 Colo. 1, 532 P.2d 720 (1975), as contrary to the pending ordinance doctrine and in support of her proposition that "[t]he law in Colorado is clear in that the law in existence at the time of the permit application governs the right to the issuance of the permit." Respondent's Answer Brief at 6.

This principle, however, is not immutable and when justice demands it, stare decisis must yield. Stroud v. City of Aspen, 188 Colo. 1, 5, 532 P.2d 720, 722 (1975) (although this court generally follows the doctrine of stare decisis, the court will deviate from that doctrine of judicial policy when warranted); Wolf v. People, 117 Colo. 279, 282-83, 187 P.2d 926, 927-28 (1947) ("The best reason, and the one perhaps most frequently invoked to justify a departure from the [stare decisis] rule, is that the case under consideration by the court demonstrates that adherence thereto will either promote injustice or defeat justice."). This is such an occasion.

By contrast, the parking provisions of the PUD plan at issue here have their ultimate source in an enabling ordinance adopted through a valid exercise of Boulder's police power. Boulder has exercised its police power by adopting a PUD enabling ordinance that ensures that the public interest in pedestrian safety, traffic control and uncongested streets will be satisfied by requiring a PUD applicant to provide adequate parking facilities for the users of the improvements comprising the PUD. Boulder Rev. Code § 9-4-12(d)(2)(D); see Tri-State, 647 P.2d at 681 (parking facilities constitute an independent element of PUD plan); Stroud v. City of Aspen, 188 Colo. 1, 532 P.2d 720 (1975) (upholding offstreet parking requirements in municipal zoning law); 5 E. Ziegler, Rathkopf's The Law of Zoning and Planning § 58.01 (1985) (discussing need for and validity of off-street parking requirements in municipal zoning regulations); cf. Bethlehem Evangelical Lutheran Church v. City of Lakewood, 626 P.2d 668, 673 (Colo. 1981) (valid exercise of police power may result in "non-compensatory reasonable restrictions in respect to private [property] interests which must yield to the public interest").

"(III) Dedication of such sites and land areas for the use and benefit of the owners and future owners in the proposed subdivision." [2] Appellants argue that the statute fails to satisfy the test for a valid exercise of the police power enunciated in Stroud v. Aspen, 188 Colo. 1, 532 P.2d 720. There, we held that a requirement that businesses either provide off-street parking or lease adequate parking space from the city was not per se unconstitutional, overruling Denver v. Denver Buick, Inc., 141 Colo. 121, 347 P.2d 919. Aspen's ordinance providing for leasing of city facilities was struck down, however, as an improper delegation to the city manager. Appellants rely on the statement in Stroud that

Appellant contends that the zoning regulations restricting trailers to trailer camps is unconstitutional as an abuse of the police power. [6,7] Zoning regulations must bear a real and substantial relationship to the public health, safety, morals or welfare. Stroud v. City of Aspen, 188 Colo. 1, 532 P.2d 720 (1975). However, as we have noted several times, zoning plans are presumed to be constitutional and it is the burden of one challenging such a regulation to demonstrate its invalidity beyond a reasonable doubt.

Conditions such as off-street parking restrictions constitute a proper application of the municipal police power and recognize the needs of contemporary society. See Stroud v. City of Aspen, 188 Colo. 1, 532 P.2d 720, 721 (1975) (citing Yates v. Mayor and Comm'rs of City of Jackson, 244 So.2d 724, 726 (Miss. 1971)) (finding that generally, courts which have considered the issue of off-street parking ordinances have upheld them as proper applications of the municipal police power).

See generally Tri-State Generation Transmission Co. v. City of Thornton, 647 P.2d 670 (Colo. 1982); Cimarron Corp. v. Board of County Commissioners, 193 Colo. 164, 563 P.2d 946 (1977); Stroud v. City of Aspen, 188 Colo. 1, 532 P.2d 720 (1975); Garel v. Board of County Commissioners, 167 Colo. 351, 447 P.2d 209 (1968); Swisher v. Brown, 157 Colo. 378, 402 P.2d 621 (1965); and General Outdoor Advertising Co. v. Goodman, 128 Colo. 344, 262 P.2d 261 (1953). And, these standards were utilized by the commissioners in rejecting CM's application.

They contend that no condition may be imposed which alleviates public needs other than those which are "uniquely and specifically attributable" to the development proposed in their application. This test was first enunciated in Pioneer Trust Sav. Bank v. Village of Mount Prospect ( 22 Ill.2d 375), and again articulated in Krughoff v City of Naperville ( 68 Ill.2d 352). Its corollary, that the benefit deriving from a condition must accrue to the development rather than the public as a whole (Aunt Hack Ridge Estates v Planning Comm. of Town of Danbury, 27 Conn S 74; Cimarron Corp. v. Board of County Comrs. of County of El Paso, 193 Col 164; Stroud v. City of Aspen, 188 Col 1), helps to focus the principle justifying the rule. That principle, basically a tax rule, is referred to as the "Special Assessment Doctrine".