Completion of Capital Beltway. Route Numbering of Capital Beltway. Following the Federal Aid Highway Act of by Congress that authorized the construction of the national 41,mile Interstate Highway System, including the proposed mile-long Washington circumferential highway, the entire beltway was granted the Interstate Route I designation by federal and state highway officials. Three-digit Interstate routes have a leading digit with the last two digits being the mainline route that it supplements, so I-x95 routes would have routes such as the ones in Virginia, I, I, I and I An odd-number leading digit signifies a spur route off a mainline route examples are I and I An even-number leading digit signifies a loop around a city examples are I and I , or a branch route connecting two Interstate highways an example is I in Maryland.
Three-digit Interstate route numbers can duplicate, but not in the same state. The completed Beltway was designated I throughout from to The I designation was moved to the eastern half of the I Beltway in , and I was removed from the eastern half of the Beltway, and I replaced the I designation on Shirley Highway from I to the 14th Street Bridge, on the 14th Street Bridge itself, on the Southwest Freeway in D.
Today's I is the former segment of I inside of the Beltway. Many regional motorists never fully adjusted to having a full-circle beltway with halves with two different numbers I and I In , the I designation was applied back to the eastern portion of the beltway, so the whole Beltway is again I, and the eastern portion is I also it carries both I and I The Beltway has the clockwise direction as in looking at a map of the Beltway signed as the Inner Loop, and the counter-clockwise direction is signed as the Outer Loop.
Exit Numbering on Capital Beltway. The exit interchange numbering on the Beltway began with a sequential system in when the Beltway was fully complete, and it was a somewhat hybrid system from to , and in was finalized to a fully milepost-based system that should last permanently.
The official decision in to cancel the remaining unbuilt segments of I in the District of Columbia and Maryland, and the concurrent decision to move the I designation to the eastern portion of the Beltway, was the cause of the need to renumber the exits on the Beltway. The period of the s and later was also a time when many states changed their Interstate highway exit numbering from sequential numbering to milepost-based numbering. Sequential exit numbering means that the exit numbers increase consecutively 1, 2, 3, 4, etc.
Milepost-based exit numbering means that each exit number is the same as the number of the nearest milepost, and while the numbers are not consecutive for example if four exits in sequence were at mileposts 7, 9, 11 and 15, then those would be the respective exit numbers , milepost-based exit numbering has widespread public support because it makes it easy to compute how many miles one needs to travel from where they are currently, to reach their destination exit, although the fact that exit numbers usually start over at zero at the beginning of each state border, removes that advantage for an inter-state trip.
Maryland began instituting milepost-based exit numbering on its Interstate highways about , and specifically on the Capital Beltway in The federal standard for exit numbering on Interstate highways, is for the numbering to advance from south to north on north-south highways, and from west to east on east-west highways. Since the eastern portion of the Beltway was I alone at that point, Maryland posted milepost zero at the state border at Alexandria, and advanced the milepost numbers along I all the way to Delaware.
Each Beltway interchange in Maryland was given milepost-based exit numbering, so from and onward there were exits 2 through 41 in Maryland, running counterclockwise as viewed on a map from above. In , Virginia renumbered its exits 1 through 4 to 58 through 61 to be consistent with the rest of its sequential exit numbering on its I, and while this eliminated the duplication of Beltway exit numbers 2, 3 and 4 in both states, it created three unrelated exit numbering schemes on the Beltway.
In , the two states decided to apply I back to the I eastern portion of the Beltway. In , the two states agreed to post along the Beltway signs with a Capital Beltway logo in red, white and blue, with an image of the U.
Virginia did not convert its statewide Interstate highway exit numbering system from sequential numbering to milepost-based numbering until beginning in , and the Beltway exits were renumbered in The current Beltway exit numbering system should be permanent, as it follows the milepost-based Interstate highway exit numbering system in both states, which should be permanent. There is no foreseeable reason why the Beltway exit numbering system should see any more changes the future completion of the canceled original downtown route of I through the District of Columbia is not impossible but is highly unlikely.
This underscores the inadequate Beltway coordination between the two states, at times, that has impacted the management of what is one metropolitan circumferential freeway. The Capital Beltway when completed in had 37 interchanges, and in that number increased to 38 when I in Maryland was completed to the Beltway. These two pairs of Beltway junctions were each defined as a single interchange in the original exit numbering system -- IS and MD, and MD and Cabin John Parkway; and in Maryland's exit renumbering, each in those pairs has a separate exit number; and it is a matter of definition as to whether each of those pairs should be considered to be one interchange or two interchanges.
The Beltway as exit-numbered in has 44 interchanges. Speed Limits on Capital Beltway. Since the National Maximum Speed Limit act was enacted, which mandated a maximum speed limit in the U. In the NMSL was modified to allow 65 mph on rural Interstate highways, and the Beltway was ruled to be in a metropolitan area and not rural and still subject to a federal maximum of 55 mph. In the U. Congress abolished the national maximum speed limit, and returned the setting of speed limits back to state control as was the case before , thus making it possible to have higher speed limits on the Beltway.
The I Capital Beltway opened in to much optimism and enthusiasm. By and , traffic volumes of cars and trucks had grown to the point where the highway was always well-used, with traffic volumes during peak hours approaching the capacity of the highway on various sections, and the maximum segment volume then was about 80, vehicles per day. Capital Beltway Operation. Today much of the Beltway carries over , vehicles per day, and even with major widening projects between and , making nearly the entire Beltway eight lanes wide four each way , much of the Beltway experiences major congestion for major periods of each day.
Wiki Capital Beltway Page. HOT lanes are tolled lanes that operate alongside existing highway lanes to provide users with a faster and more reliable travel option.
Drivers with fewer than three occupants can choose to pay to access the lanes. Tolls for the HOT lanes will change according to traffic conditions to regulate demand for the lanes and keep them congestion free - even during peak hours. By this point, urban development in Washington had outgrown the circle of forts and surface streets had reached them.
The planned road had little use at that point and the grand drive to link the forts was dropped. Postwar America was hungry for their piece of the American dream, and that included a house in the suburbs and a car. America needed roads, and a lot of them. The next major mention of it in the Washington Post is March 8th, The Senate Public Works Committee was asking for a proposed road to encircle the city and the Public Roads Bureau pulled together an initial map showing where the road could be built.
The road would be a limited-access, high-speed loop to facilitate the travel of dispersed government employees throughout the metropolitan area as the city population expanded into the suburbs. A bill was proposed and debated on the Senate floor in April of with the goal of moving several Federal agencies outside of the District to Maryland and Virginia. The size of government had ballooned dramatically as a result of World War II and had outgrown the buildings in D.
Senator Spessard L. There was a slight sense of urgency to get started on an outer ring road as the suburbs were starting to accelerate their development. And the more development, the further out the road would have to go due to the cost of acquiring the right-of-way. When you build a road, the goal is obviously to efficiently use tax-payer money. And to keep land costs down, the Maryland State Roads authorities attempted to route the highway through as little developed land as possible.
In Montgomery County, it was a different story. Bethesda and the surrounding areas were quite developed with affluent subdivisions and large homes. Carving a path through expensive property was not something that was financially or politically possible. The only way to complete the proposed highway was to cut a three-mile pass through federally owned Rock Creek Park probably political suicide today.
In , Maryland and Virginia completed Beltway widening to eight lanes between I Spur and VA, a distance of 5 miles; this included the American Legion Memorial Bridge and approaches to each interchange closest to the river, which was widened to 10 lanes.
These two photos show generally typical views of the current Capital Beltway. Photo taken May 13, by Scott Kozel. Click photo for large image. The Beltway was designated I throughout from to The I designation was moved to the eastern half of the I Beltway in , and I was removed from the eastern half of the Beltway, and I replaced the I designation on Shirley Highway from I to the 14th Street Bridge, on the 14th Street Bridge itself, on the Southwest Freeway in D.
Many regional motorists never fully adjusted to having a full-circle beltway with halves with two different numbers I and I In , the I designation was applied back to the eastern portion of the beltway, so the whole beltway is again I, and the eastern portion is I also. The beltway has the clockwise direction as in looking at a map of the Beltway signed as the Inner Loop, and the counter-clockwise direction is signed as the Outer Loop.
The Capital Beltway was originally built with 38 interchanges, and today it has 40 interchanges the Eisenhower Avenue Connector interchange and the FedEx Field interchange were added recently. A number of interchanges have been expanded. There are studies underway at present to widen sections of the beltway to ten or twelve lanes. The traffic volumes on the beltway range as high as , vehicles per day.
Junctions —. Former overhead signs for I and I north on Interstate east. The merge with I northbound was numbered Exit 4A in the old sequential numbering system.
North West. I continues with three lanes north toward Baltimore while I maintains eight overall lanes through the exchange. Photo by Jim K. South at. Interstate 95 heads south from Beltsville to the Capital Beltway west of U. The I southbound mainline merges onto the left side of I east through the adjacent cloverleaf interchange with U.
Cherry Hill Road passes over Interstate 95 south as the freeway separates into ramps for the Capital Beltway. Following the ramp for I west, traffic again splits with a single lane continuing south to a weigh station, carpool lot, and an return ramp to the Capital Beltway inner loop ahead of U.
0コメント