Ordinarily, frontage of such distance as is required under the applicable zoning by-law, and along a roadway of suitable condition, is sufficient to support an approval not required endorsement. However, "planning boards are authorized to withhold 'ANR' endorsements in those unusual situations where the 'access implied by the frontage is . . . illusory in fact.'" Corcoran v. Planning Bd. of Sudbury, 406 Mass. 248, 251, 547 N.E.2d 911 (1989), quoting Fox v. Planning Bd. of Milton, 24 Mass. App. Ct. 572, 574, 511 N.E.2d 30 (1987). Thus, sufficient access is not provided by frontage on a limited access highway, McCarthy v. Planning Bd. of Edgartown, 381 Mass. 86, 407 N.E.2d 348 (1980), citing Hrenchek v. Planning Bd. of Walpole, 8 Mass. App. Ct. 949, 397 N.E.2d 1292 (1979), nor by frontage on an unconstructed "paper street," Perry v. Planning Bd. of Nantucket, 15 Mass. App. Ct. 144, 444 N.E.2d 389 (1983), nor by frontage completely obstructed by a metal highway guardrail, Poulos v. Planning Bd. of Braintree, 413 Mass. 359, 597 N.E.2d 417 (1992). Similarly, frontage is illusory in fact if there is no feasible access from the frontage to any upland portion of the lot. Gates v. Planning Bd. of Dighton, 48 Mass. App. Ct. 394, 399-401, 722 N.E.2d 477 (2000). See generally Gifford v. Planning Bd. of Nantucket, 376 Mass. 801, 383 N.E.2d 1123 (1978).