To the contrary, in a subsequent case, the Illinois Supreme Court cited Chicago & North Western Ry. , as well as the 1934 case and several other cases, for the proposition that "[i]t is well settled that the [ICC]'s jurisdiction over all phases of grade-crossing regulation is plenary and exclusive." City of Chicago v. Illinois Commerce Comm'n , 79 Ill.2d 213, 219, 37 Ill.Dec. 593, 402 N.E.2d 595 (1980). The court added, "In the exercise of its power to regulate grade crossings in the interest of public safety, the [ICC] is vested with wide discretion to determine what the public interests require and what measures are necessary for the protection and promotion of those interests."

The Soo Line and the Commission request that we interpret the power of the Commission pursuant to section 18c-7401(3) more broadly than IDOT would have us do. We agree. In City of Chicago v. Illinois Commerce Comm'n (1980), 79 Ill.2d 213, 402 N.E.2d 595, the Commission had issued a rule requiring public bodies, at their expense, to place and maintain signs on railroad overpasses at crossings indicating the clearance available for vehicles using the crossing. The City of Chicago brought suit contesting the power of the Commission to enact the rule.

While this court generally requires strict compliance with this doctrine, we recognize several exceptions. An aggrieved party may seek judicial review of an administrative decision without complying with the exhaustion of remedies doctrine where a statute, ordinance or rule is attacked as unconstitutional on its face ( County of Kane v. Carlson (1986), 116 Ill.2d 186, 199; City of Chicago v. Illinois Commerce Comm'n (1980), 79 Ill.2d 213, 217; Allphin, 60 Ill.2d at 358), where multiple administrative remedies exist and at least one is exhausted ( Allphin, 60 Ill.2d at 358; One Way Liquors, Inc. v. Byrne (1982), 105 Ill. App.3d 856, 861), where the agency cannot provide an adequate remedy or where it is patently futile to seek relief before the agency ( Graham v. Illinois Racing Board (1979), 76 Ill.2d 566, 573; Sanders v. City of Springfield (1985), 130 Ill. App.3d 490, 493), where no issues of fact are presented or agency expertise is not involved ( Allphin, 60 Ill.2d at 358; McKenna v. Board of Trustees (1980), 90 Ill. App.3d 992, 998-99), where irreparable harm will result from further pursuit of administrative remedies ( Allphin, 60 Ill.2d 350; Byrne, 105 Ill. App.3d at 861), or where the agency's jurisdiction is attacked because it is not authorized by statute ( Byrne, 105 Ill. App.3d at 861). The appellate court never reached the merits of plaintiff's appeal.

To the contrary, in a subsequent case, the Supreme Court of Illinois cited Chicago & North Western Ry., as well as the 1934 case and several other cases, for the proposition that "[i]t is well settled that the [ICC]'s jurisdiction over all phases of grade-crossing regulation is plenary and exclusive." City of Chicago v. Illinois Commerce Comm'n, 79 Ill. 2d 213, 219 (1980). The court added, "In the exercise of its power to regulate grade crossings in the interest of public safety, the [ICC] is vested with wide discretion to determine what the public interests require and what measures are necessary for the protection and promotion of those interests."

It is well settled that the Commission's jurisdiction over all phases of grade crossing regulation is plenary and exclusive. City of Chicago v. Illinois Commerce Comm'n, 79 Ill.2d 213, 219 (1980). In the exercise of its power to regulate grade crossings in the interest of public safety, the Commission is vested with wide discretion to determine what the public interests require and what measures are necessary for the protection and promotion of those interests.

However, it is fundamental that the declaratory judgment remedy is cumulative of other statutory or common law remedies. Thus the court in City of Chicago v. Illinois Commerce Com. (1980), 79 Ill.2d 213, 402 N.E.2d 595, found that sections 67 and 68 did not preclude an action for declaratory judgment involving a rule of the Commission which was challenged on its face as beyond the statutory authority of the Commission. • 10 In summary, plaintiffs have sufficiently and concretely stated an actual controversy for declaratory judgment purposes, given the fact that the Commission has issued citations specifically invoking the power of that agency to impose civil penalties.

( 86 Ill.2d 479, 487-88, 427 N.E.2d 1226.) A fifth exception, that administrative remedies need not be exhausted where an administrative rule is challenged on its face as not being authorized by the agency's enabling legislation, has also been recognized. ( City of Chicago v. Illinois Commerce Com. (1980), 79 Ill.2d 213, 217, 402 N.E.2d 595.) Plaintiff, in its appellate brief, argues that this case falls within the irreparable harm and the unauthorized-by-the-enabling-legislation exceptions. In its reply brief, plaintiff additionally argues that this case falls within the "patently useless" exception.

Nothing in the Public Utilities Act or the Commission's regulations authorizes a utility to exempt itself from this liability by means of a tariff. Nor may any such exemption be conferred on a public utility by the Commerce Commission. This is so because, as a creature of the legislature, the Commerce Commission derives its authority solely from the statute creating it, i.e., the Public Utility Act, and any acts it takes or orders it makes inconsistent with that act are void. City of Chicago v. Illinois Commerce Comm'n (1980), 79 Ill.2d 213, 217-18. In an effort to avoid this conclusion, Illinois Bell makes the somewhat startling assertion that the exculpatory provision in the tariff does not, in fact, conflict with the terms of section 5-201 of the Act.

The Commerce Commission, "because it is a creature of the legislature, derives its power and authority solely from the statute creating it, and its acts or orders which are beyond the purview of the statute are void." ( City of Chicago v. Illinois Commerce Com. (1980), 79 Ill.2d 213, 217-18, citing People ex rel. Illinois Highway Transportation Co. v. Biggs (1949), 402 Ill. 401, 409.) Courts have given great weight and deference to the interpretation of an ambiguous statute by a public agency charged with the administration and enforcement of the statute. ( Illinois Consolidated Telephone Co. v. Illinois Commerce Com. (1983), 95 Ill.2d 142, 152.

Our supreme court has stated that "[t]he Commission, because it is a creature of the legislature, derives its power and authority solely from the statute creating it, and its acts or orders which are beyond the purview of the statute are void." City of Chicago v. Illinois Commerce Comm'n, 79 Ill. 2d 213, 217-18 (1980). The Commission's authority to enter the order appealed in this case must, therefore, find its source in the Act.