GDOT Powerpoint Template
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Intersection Types North Carolina • 9,500+ Traffic Signals Tennessee • 100+ On System AWSC South Carolina Alabama Georgia Florida Intersection Types North Carolina • 9,500+ Traffic Signals Tennessee • 100+ On System AWSC South • 175+ Roundabouts Carolina Alabama Georgia SR 372 @ Providence Florida I-285SR 16 @ @ Riverside SR 54 Dr SR 154 @ Cedar Grove Intersection Types North Carolina • 9,500+ Traffic Signals • 100+ On System AWSC South • 175+ Roundabouts Carolina • 25+ RCUTS Georgia Florida SR 20 @ Simpson Mill SR 400 @ N 400 Center Ln SR 92 @ N. Griffin Square Intersection Types • 9,500+ Traffic Signals • 100+ On System AWSC • 175+ Roundabouts • 25+ RCUTS • 5 DDIs Jimmy Carter @ I-85 I-285I-85 @ @ Ashford Pleasant Dunwoody Hill Rd Rd Intersection Types • 9,500+ Traffic Signals • 100+ On System AWSC • 175+ Roundabouts • 25+ RCUTS • 5 DDIs • 1 CFI SR 400 @ SR 53 SR 400 @ SR 53 Intersection Types • 9,500+ Traffic Signals • 100+ On System AWSC • 175+ Roundabouts • 25+ RCUTS • 5 DDIs • 1 CFI • 5+ Continuous Green T W Oglethorpe Blvd. @ N Slappey Blvd. Deliver a transportation system focused on innovation, safety, sustainability and mobility http://alphastockimages.com/ Illinois DOT Illinois DOT Illinois DOT Integrate safety into our decision making process for intersection control on ALL projects The purpose of ICE is to provide: • Traceability • Transparency • Consistency • Accountability • GDOT Design Policy Manual – Ch. 7 Design Policy Manual: At Grade Intersections – Ch. 8 Design Policy Manual: Roundabouts • MUTCD • Frustration due to the lack of non-traditional alternatives considered • Create a level playing field for all alternatives • Desire to infuse safety throughout our decision making process by bringing attention to “non-traditional” intersection types • Provide documentation to support the intersection control decision 2015 2007 2008 2018 2014 2013 2017 Existing Developing Interest in ICE Policies ICE Policies ICE Policies • ICE is required for all projects that do not have concept approval by July 1, 2017 • If ICE would delay the concept report submittal for any projects that have schedules set by July 1, 2017, ICE may be completed during the preliminary design phase • Submittals during preliminary design must occur no later than 1/3 of the way through the time allotted for preliminary design • For GDOT projects, if consultant services have already been procured prior to the effective date, but the concept has not been approved, Office of Traffic Operations will perform the ICE evaluation upon request by the project manager. Intersection Control Evaluation http://www.dot.ga.gov/ Scroll to bottom of the page Not Required Required Waiver No changes to Project is on ICE may be intersection State waived based footprint or route/NHS on appropriate control and/or uses evidence and a State or Federal written request money A project that will not do any widening, where there is no change to intersection geometry or control. Examples include: – Sidewalk/streetscape improvements – bridge replacement (with no realignment or relocation of intersection) – resurfacing – Signal timing and maintenance. – Signal Permit revision w/ no changes to physical footprint of intersection For driveway permits, where the driveway is not a new leg to an already existing intersection, that satisfy either of the following criteria: 1. The driveway is along a divided, multilane roadway where the access will be limited to a closed median (no median opening) with only right-in/right-out access 2. The driveway is along an undivided roadway and the development will not be required to construct left and/or right turn lanes (as per the Driveway Manual and District Traffic Engineer) In certain circumstances where an ICE would otherwise be required, the requirement may be waived based on appropriate evidence presented with a written request. • Proposed improvements do not substantially alter the character of the intersection, and are considered minor in nature, such as extending existing turn lane(s) • The intersection consists of a public roadway intersecting a divided, multilane roadway where the access will be limited to a closed median with only right-in/right-out access that will operate acceptably; • The intersection is along an undivided, two-lane roadway that will not be widened and: o Low risk in terms of exposure (less than 1,000 vehicles entering per day). o Latest 5 years of crash history is not indicative of a crash problem o No undesirable geometric features o Proposed changes will not adversely affect safety Level 1: Chief Engineer (or Designee) • Projects going through PDP • New or revised signal permits • New median openings Level 2: District Engineer with notification to Chief Engineer Projects that are not level 1 where: • Leg is added to intersection • Intersection control is changes Level 3: District Engineer • QR, Driveway Permits, Maintenance Work that does not qualify as level 2 Intersection Control Evaluation Stage 1 Stage 2 Alternative ICE Screening Selection Screening effort to Detailed evaluation of the eliminate non- alternatives identified in competitive options Stage 1 in order to support and identify the selection of the alternatives for further preferred alternative that consideration will be advanced to detailed design Unsignalized • Minor Stop • All-Way Stop • Mini Roundabout • Single Lane Roundabout • Multilane Roundabout • RCUT • RIRO w/Downstream U-Turn • High-T (unsignalized) • Offset-T Intersections • Diamond Interchange (Stop) • Diamond Interchange (RAB) • Turn Lane/Median Improvements • Other Signalized • Signal • Median U-Turn • RCUT • Displaced Left Turn (CFI) • Continuous Green-T • Jughandle • Diamond Interchange (signal) • Quadrant Roadway • Diverging Diamond • Single Point Interchange • Turn Lane/Median Improvements • Other 1. Does alternative address the project need in a balanced manner and in scale with the project? 2. Does alternative improve safety performance in terms of reducing severe crashes? 3. Does alternative incorporate convenience and accessibility for pedestrians and/or bicyclists 4. Does alternative improve (or preserve) traffic operations (congestion, delay, reliability, etc.)? 5. Does alternative appear feasible given the site characteristics, constrains and location context? 6. Does alternative appear feasible with respect to other project factors? 7. Overall feasible alternative? Shortlist of Alternatives from Stage 1 • Total Project Cost RCUT RAB • Traffic Operations • Safety Analysis Traffic Signal • Environmental Impacts • Stakeholder Posture Preferred Alternative Stage 1 • Completed Stage 1 Decision Record • Single intersection projects may proceed seamlessly to Stage 2 • For corridor projects a concurrence memo is recommended • Required for Concept Report Stage 2 • Completed Alternative Selection Decision Record with Supporting documentation • Included in Project Concept Report or as a stand-alone document • Completed waiver form if the ICE recommended alternative is not selected as the preferred alternative • Required in Concept for stand alone intersection projects. Intersection Control Evaluation 1. Provide simplified and consistent way of using data to quantify & evaluate intersection control benefits – Traffic – Safety – Cost – Environmental Impact – Stakeholder Support 2. Provide traceability, transparency, consistency & accountability when evaluating & selecting control types 3. Reduce time to analyze, compare multiple alternatives 4. Select alternative that reflects the overall best value in terms of specific performance-based criteria • Serves as agreed upon Decision Document • GDOT precedent of developing tool for consistent analysis GDOT Roundabout Analysis Tool INTERSECTION CONTROL TYPE DESCRIPTIONS Click on intersection images for additional resource publications ICE Version 2.1 | Revised 12/13/2017 Unsignalized At-Grade Intersections Signalized At-Grade Intersections Conventional Minor Street or All-Way Stop: At minor- street stop (2-way stop) intersections, vehicles on minor Signalized Intersection: The most common type of street stop and give right-of-way to major street. At all-way signalized intersection with high driver familiarity. Signal stop (AWS) intersections, all vehicles must stop and take could be simple two-phase or more complex 8-phase to turns entering the intersection. Both (4-leg) intersection serve vehicular demand. Left turns can be permitted or types have 32 baseline conflict points and have limited protected (or combination of both). At a conventional 4-leg operational and safety benefits as traffic volumes become intersection there are 32 baseline conflict points. significant. Mini Roundabouts: Roundabout type characterized by a Median U-Turn: Left turn movements otherwise occurring small diameter and traversable central island; offers most of at the main intersection are made via U-turns in the median, the benefits of single-lane roundabouts with added benefit of preceding or following right turns. U-turns may be only on a smaller footprint; best suited to lower-speed environments major roadway or on both major and minor roadways. A and where environmental constraints preclude use of a conventional MUT has 16 baseline conflict points and has larger roundabout with a raised central island. Mini- shown significant operational and safety benefits. roundabouts are emerging in U.S. in states including MD, Also known as: Indirect Left, Michigan Left, MUT MI and GA. Single-Lane Roundabouts: Form of circular intersection Signalized RCUT: Similar