US 3 and "To I-93", but these have now been replaced with regular I-93 signs. The Federal Highway Act of 1973 exempts this stretch from the Interstate Highway standards that apply elsewhere, and this highway is considered to be I-93 for all practical purposes. This section of I-93 in New Hampshire is now the only remaining multi-mile section of two-lane freeway on an Interstate Highway in the United States. In addition, parking along portions of I-93 through Franconia Notch was permitted until early 2019 when barriers and signage were posted due to safety concerns. Some stretches of Interstate highway use a barrier transfer machine on some bridges to convert inner lanes from one direction to the other, where it would be too costly to upgrade/rebuild to a higher-capacity bridge. In any case the traffic distribution is strongly asymmetric depending on the hour of the day. This kind of bridge typically contains undivided lanes without the flexible Jersey barrier that is manipulated by machines. Movable bridges By Interstate standard, all bridges on the Interstate system must be fixed as to not interrupt the flow of traffic. Several bridges on the system, however, are movable: I-5 crosses the Columbia River from Portland, Oregon, to Vancouver, Washington, on the Interstate Bridge, a vertical-lift bridge. The Columbia River Crossing project sought to replace this bridge until being abandoned in 2013. I-110 has a drawbridge across the Back Bay of Biloxi in Biloxi, Mississippi. I-64—the Hampton Roads Beltway—crosses the South Branch Elizabeth River in Chesapeake, Virginia, on the High Rise Bridge, which is a drawbridge, expected to be replaced by a larger fixed bridge in 2021. I-264 has a drawbridge, the Berkley Bridge, crossing the Elizabeth River in Norfolk, Virginia. I-278 has a drawbridge across the Bronx River in New York City. I-280 has a drawbridge, the Stickel Memorial Bridge, crossing over the Passaic River between Newark and Harrison, New Jersey. I-95/I-495 pass together as the Capital Beltway over the Potomac River on the Woodrow Wilson Bridge, a double-leaf bascule span. Even though the original bridge was replaced in the 2000s, the new bridge also has a draw span, albeit with more vertical clearance resulting in fewer openings than the old bridge—about 65 per year, an average of about one every six days. I-695 has a drawbridge over Curtis Creek, south of Baltimore and just west of the Francis Scott Key Bridge. This section of