OPINION AND ORDER
HENRY PITMAN, Magistrate Judge.
Plaintiffs Automobile Club of New York, Inc., doing business as "AAA New York, " and AAA North Jersey, Inc. (collectively, "AAA") claim that the privilege log submitted by defendant the Port Authority of New York and New Jersey (the "Port Authority") is deficient. The Port Authority produced a privilege log that identified categories of withheld documents, rather than identifying each individual document withheld. AAA does not object to the Port Authority's use of a categorical privilege log, but instead contends that eight of the categories do not contain the substantive information required by Rule 26 of the Federal Rules of Civil Procedure. AAA seeks an order directing the Port Authority to amend its log to correct this deficiency.
For the following reasons, I conclude that the Port Authority's privilege log should be supplemented as detailed below.
A. Plaintiffs' Underlying Allegations
The facts and allegations in this case are fully set forth in the decision of the Honorable Richard J. Holwell, United States District Judge (retired), addressing plaintiffs' motion for a preliminary injunction and defendant's cross-motion to dismiss, Auto. Club of N.Y., Inc. v. Port Auth. of N.Y. & N.J. , 842 F.Supp.2d 672 (S.D.N.Y. 2012), and can be briefly summarized.
AAA contends that certain toll increases within the Port Authority's Integrated Transportation Network ("ITN"),  which took effect on September 18, 2011, were enacted for improper purposes - specifically, to fund real estate development at the World Trade Center site, rather than to cover ITN capital needs - and violate the Commerce Clause of the United States Constitution and the Surface Transportation and Uniform Relocation Assistance Act of 1987 (the "Highway Act"), 33 U.S.C. § 508 (Complaint ("Compl.")(Docket Item 1) §§ 1, 34-45). Plaintiffs argue that under Bridgeport & Port Jefferson Steamboat Co. v. Bridgeport Port Authority , 567 F.3d 79, 86 (2d Cir. 2009), such toll increases violate the dormant Commerce Clause because they do not bear a "functional relationship" to the ITN, and, thus, do not represent a "fair approximation" of the use of ITN facilities and are "excessive in relation to the benefits conferred" on toll payers (Memorandum of Law in Support of Plaintiffs' Motion for a Preliminary Injunction, dated September 26, 2011 (Docket Item 32)("Pls.' P.I. Mem.") at 10). Accordingly, AAA contends that the tolls are not "just and reasonable" under the Highway Act, and are, therefore, illegal because they were enacted to fund projects that are not part of the ITN (Pls.' P.I. Mem. at 6-7, citing Auto. Club of N.Y., Inc. v. Port Auth. of N.Y. & N.J. , 887 F.2d 417 (2d Cir. 1989)). Plaintiffs sought a preliminary injunction to reverse the toll increases, and continue to seek declaratory as well as injunctive relief (Compl. §§ 46-51).
Judge Holwell denied AAA's motion for a preliminary injunction and converted the Port Authority's cross-motion to dismiss into a motion for summary judgment, but reserved decision pending discovery. Auto. Club of N.Y., Inc. v. Port Auth. of N.Y. & N.J., supra , 842 F.Supp.2d at 681. Discovery in this action has been limited "to Interstate Transportation Network Revenues and expenses for the years 2007 forward" (Docket Item 41) and "the reasons for the toll increases" (Docket Item 69 at 16-17).
B. The Instant Dispute
Pursuant to Fed.R.Civ.P. 26 and Local Civil Rule 26.2(c), the Port Authority provided plaintiffs with a privilege log that identified withheld documents on a categorical, rather than an individual, basis. At issue here are eight categories of documents - numbers 17, 18, 19, 20, 24, 25, 26 and 27 - with respect to which the Port Authority has claimed the deliberative process privilege.
AAA claims that the Port Authority's privilege log is deficient with respect to these eight categories because it fails "to provide the substantive information required by Fed.R.Civ.P. 26(b)(5) and S.D.N.Y. Local Rule 26.2 in a comprehensible form" (Letter from Kevin P. Mulry, Esq., dated February 27, 2013 ("Mulry Ltr.") at 2-3). AAA does not object to the Port Authority's use of a categorical log, but rather objects to the specific descriptions provided (Mulry Ltr. at 3). AAA claims that the log is deficient because (1) the log should contain more detailed descriptions of the withheld documents; (2) the log does not contain sufficient information for AAA to determine whether a document is predecisional and (3) the term "Client" is defined so broadly that it is meaningless (Mulry Ltr. at 3-4).
The Port Authority contends that its log is sufficiently detailed (Letter from Randy M. Mastro, Esq., dated March 4, 2013 ("Mastro Ltr.")). In support of this contention, the Port Authority points to the fact it provided AAA with additional information about the documents withheld on privilege grounds, including the total number of documents withheld in each category, additional descriptions of the type and subject-matter of documents withheld, year-by-year date ranges for certain categories, a list of all Port Authority counsel appearing on the privileged documents and clarification of the terms "Client" and "Client's In-House Counsel" (Ex. E to Mastro Ltr.).
I heard oral argument on AAA's objections to the privilege log on March 6, 2013. On March 11, 2013, the Port Authority submitted a supplemental privilege log that incorporated the additional details it had previously provided to AAA in separate materials.
A. Applicable Law
1. Deliberative Process ...