234.1 Access to Interstate Highways: Difference between revisions

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[[image:234.1 Interchange Justification for Interstate Highways.jpg|right|400px]]
[[image:234.1 Interchange Justification for Interstate Highways.jpg|right|400px]]


Interchanges are considered where conflicting high traffic volumes exceed those that can be handled efficiently and safely with at-grade intersections.  They are also used to control access to the main highway. The [[:Category:126 Location Study and Alternatives Analysis|location study]] for a proposed improvement recommends the type and location of a proposed interchange necessary to address these concerns.  A precise analysis of traffic movement that justifies the necessity for an interchange is required. Depending on the complexity, appropriate modeling can include microsimulation or analysis using the Highway Capacity Manual.  Access management guidelines are considered in analysis of operational and safety concerns.
New or revised access to an interstate highway requires approval from FHWA.  A change in access is considered as any modification to the control-of-access for right of way on an interstate highway. This includes locked gate access, access to ramps or collector-distributor roadways or other facilities that are functionally part of an interstate highway. Re-configuration of an interchange that affects the operational characteristics of an interstate highway is also considered as a change in access. Only MoDOT, as the owner and operator of interstate highways in Missouri, is authorized to submit a request for new or revised access to FHWA for consideration.  Proposed changes in access to interstate highways in Missouri are presented to FHWA in the form of an Access Justification Report (AJR).  


MoDOT intends to provide access for all traffic movements at an interchange on the state highway system.  In some cases, traffic volumes may not warrant the provision of ramps at the time of initial construction. However, right of way will be purchased to provide for the future ramps. The plans for initial construction of the interchange will show the location of future ramps for these traffic movements.
Due to the complexity of adding or revising Interstate access, FHWA has developed an [http://www.fhwa.dot.gov/design/access.cfm Interstate System Access Informational Guide] that clearly defines and explains what should be included in the request for new or revised access and the AJR.  The analysis of Interstate System access changes requires the consideration of many factors including the planning, environment, design, safety, and operational context for any proposed changes. Quantifying and comparing the impacts of each of these key factors is an important aspect of ensuring any change in access protects the integrity of the Interstate System. The purpose of the AJR is to provide the information necessary for FHWA to make informed decisions on requests for new or modified access to an interstate highway. The Interstate System Access Informational Guide recognizes that AJRs should be evaluated as part of an integrated transportation system. The type of analysis necessary will vary on a request-by-request basis. At a minimum, the system analysis will include upstream and downstream interchanges, as well as the local road system feeding into the affected interchanges.


Justification for new or revised access to an interstate highway requires approval from FHWA.  This approval is a two-step process that consists of concept approval and final approval. MoDOT requests concept approval from FHWA with an Access Justification Report (AJR). After concept approval has been obtained, final approval is automatic after the NEPA requirements have been fulfilled assuming no significant changes have been made to the original concept.  This approval is necessary in order to receive federally controlled funding for the project(s) that will create the new or revised interstate access.  Detailed guidance concerning the analysis and documentation necessary to justify a change in access to an interstate highway can be found on the [http://www.fhwa.dot.gov/modiv/intersta.htm FHWA Missouri Division website].  Recent national policy guidance provides the following information:
Approval for a change in access can be a two-step process developed to help MoDOT manage risk and provide flexibility. It is intended to identify serious flaws and to help ensure the investments in the subsequent phases of production, including any environmental documents, are not wasted. The first step is a finding of operational and engineering acceptability.  This is accomplished through the preparation of an AJR and submission to FHWA. The second step is the final FHWA approval which constitutes a Federal Action, and as such, requires that the [[127.14 National Environmental Policy Act (NEPA) Classification and Documents|National Environmental Policy Act (NEPA)]] procedures are followed. Compliance with the NEPA procedures need not precede the determination of engineering and operational acceptability. However, final approval of access change cannot precede the completion of NEPA. Once NEPA has been completed, approval of the access change is granted as long as there are no changes to the location or design of the accepted concept.


*'''Applicability''':  The policy is applicable to new or revised access points to existing interstate facilities regardless of the funding of the original construction or regardless of the funding for the new access points.
Completion of the AJR in accordance with the Interstate System Access Informational Guide does not guarantee approval of any new access or changes to the access. However, it does provide a framework for the analysis of the potential benefits and consequences of the proposed project. Regardless of the funding source, since approval is considered a Federal Action, the project's final approval is contingent on the successful completion of the same process as used in the planning, engineering and environmental phases for any federally funded project. The improvements included in the AJR also must be adopted as part of a conforming transportation plan and [[141.7 Transportation Improvement Program Approval|transportation improvement program (TIP)]] or a STIP in non-urban areas to receive final approval.


*'''Access Point''':  Each entrance point to or exit point from the mainline, including a “locked gate” (for fire, medical or other emergency vehicles to reduce travel time or for maintenance activities or land access in remote locations), is considered to be an access point (e.g., a diamond interchange configuration has four access points).
A more detailed explanation of the process for reviewing and approving an AJR in Missouri can be found on the [http://www.fhwa.dot.gov/modiv/intersta.htm FHWA Missouri Division website]. Information describing access changes that will require an AJR as well as those that will require something less than a complete AJR can be found at this location. This site should also be referenced to determine the appropriate  level of FHWA approval required for the particular access change ([http://www.fhwa.dot.gov/ FHWA Headquarters Office] or FHWA Missouri Division Office).  


*'''Revised Access''':  A change in the interchange configuration even though the number of actual points of access may not change.  This is subject to the complexity of the revision being made.
The intent of the national policy is to maintain an interstate highway at its highest level of service in terms of safety and mobility.  With this in mind, each interstate access revision will need to be analyzed on a case-by-case basis to confirm that the safety and traffic operations of the interstate highway are not adversely affected.
Although not comprehensive, the following information identifies the major categories of projects that will or will not require an AJR.
==234.1.1 Revisions Requiring FHWA Access Approval and an AJR==
Concept approval by the FHWA Headquarters Office (Washington, D.C.) is required for the following types of interstate revised access:
* A new freeway-to-freeway interchange.
* Major modification of freeway-to-freeway interchange configuration (e.g., adding new ramp(s), abandoning or removing ramp(s), completing basic movements).
* New partial interchange or new ramps to or from continuous frontage road that create a partial interchange.
* New freeway-to-crossroad interchange located in a Transportation Management Area (TMA).  A TMA is an urbanized area with a population of more than 200,000 people determined by the latest decennial census, or other area when the TMA designation is requested by the Governor and the MPO (or affected local officials), and officially designated by the administrators of FHWA and the Federal Transit Administration (FTA).
The FHWA Division Office (Jefferson City) can give concept approval for the following types of interstate revised access:
* A new freeway-to-crossroad interchange not located in a TMA.
* Modification of existing freeway-to-crossroad interchange configuration.
* The completion of basic movements at a partial interchange.
* Locked gate access.
* The abandonment of ramps or interchanges.
Proposed shifts or breaks in the interstate access control lines may require an abbreviated AJR, depending on the extent of impacts resulting from the proposed revisions.  At a minimum, access revisions that involve major traffic generators will be analyzed for traffic impacts to the interstate highway.  The extent of the documentation will be consistent with the complexity and expected impact of the proposed access revision.
==234.1.2 Revisions Not Requiring FHWA Access Approval==
The following types of revisions to an interchange do not require FHWA approval:
* The addition of left turn storage lanes, right turn storage lanes, and through travel lanes, traffic signalization improvements, or relocation or shifting the existing ramp termini at the crossroad.
* Increasing the length of any deceleration or acceleration lanes on existing ramps.  MoDOT will conduct an operational analysis and evaluation of spacing between interchanges to ensure safe weaving, diverging, merging maneuvers and good directional signing are provided.
* Addition of continuous travel lanes to an existing ramp.
* New signing, striping, and/or resurfacing of existing interstate ramps, where the geometric features are not changed.
* Installation of roadside guardrail and concrete barriers (3R and safety projects).
All FHWA approvals for new or revised access are conditioned on MoDOT complying with all applicable federal regulations, including planning and right-of-way regulations and NEPA.  FHWA approval constitutes a federal action that requires NEPA procedures to be followed.  This even applies when changes to an interstate facility are not financed with federal funds.  The earliest final approval can be given for an access request is after the completion of the NEPA process.
[[image:234.1.2.jpg|center|775px]]
[[image:234.1.2.jpg|center|775px]]
[[category:234 Interchanges]]
[[category:234 Interchanges]]

Revision as of 07:26, 22 April 2011

New or revised access to an interstate highway requires approval from FHWA. A change in access is considered as any modification to the control-of-access for right of way on an interstate highway. This includes locked gate access, access to ramps or collector-distributor roadways or other facilities that are functionally part of an interstate highway. Re-configuration of an interchange that affects the operational characteristics of an interstate highway is also considered as a change in access. Only MoDOT, as the owner and operator of interstate highways in Missouri, is authorized to submit a request for new or revised access to FHWA for consideration. Proposed changes in access to interstate highways in Missouri are presented to FHWA in the form of an Access Justification Report (AJR).

Due to the complexity of adding or revising Interstate access, FHWA has developed an Interstate System Access Informational Guide that clearly defines and explains what should be included in the request for new or revised access and the AJR. The analysis of Interstate System access changes requires the consideration of many factors including the planning, environment, design, safety, and operational context for any proposed changes. Quantifying and comparing the impacts of each of these key factors is an important aspect of ensuring any change in access protects the integrity of the Interstate System. The purpose of the AJR is to provide the information necessary for FHWA to make informed decisions on requests for new or modified access to an interstate highway. The Interstate System Access Informational Guide recognizes that AJRs should be evaluated as part of an integrated transportation system. The type of analysis necessary will vary on a request-by-request basis. At a minimum, the system analysis will include upstream and downstream interchanges, as well as the local road system feeding into the affected interchanges.

Approval for a change in access can be a two-step process developed to help MoDOT manage risk and provide flexibility. It is intended to identify serious flaws and to help ensure the investments in the subsequent phases of production, including any environmental documents, are not wasted. The first step is a finding of operational and engineering acceptability. This is accomplished through the preparation of an AJR and submission to FHWA. The second step is the final FHWA approval which constitutes a Federal Action, and as such, requires that the National Environmental Policy Act (NEPA) procedures are followed. Compliance with the NEPA procedures need not precede the determination of engineering and operational acceptability. However, final approval of access change cannot precede the completion of NEPA. Once NEPA has been completed, approval of the access change is granted as long as there are no changes to the location or design of the accepted concept.

Completion of the AJR in accordance with the Interstate System Access Informational Guide does not guarantee approval of any new access or changes to the access. However, it does provide a framework for the analysis of the potential benefits and consequences of the proposed project. Regardless of the funding source, since approval is considered a Federal Action, the project's final approval is contingent on the successful completion of the same process as used in the planning, engineering and environmental phases for any federally funded project. The improvements included in the AJR also must be adopted as part of a conforming transportation plan and transportation improvement program (TIP) or a STIP in non-urban areas to receive final approval.

A more detailed explanation of the process for reviewing and approving an AJR in Missouri can be found on the FHWA Missouri Division website. Information describing access changes that will require an AJR as well as those that will require something less than a complete AJR can be found at this location. This site should also be referenced to determine the appropriate level of FHWA approval required for the particular access change (FHWA Headquarters Office or FHWA Missouri Division Office).

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