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Managing Networks A GIS & Project-Based Network Management System for Highways and Transit Presented to 12 th TRB Transportation Planning Applications Conference, Houston, TX Bing Mei, P.E. Triangle Regional Model Service Bureau ITRE @ NCSU May 19, 2009. Introduction.
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Managing NetworksA GIS & Project-Based Network Management System for Highways and TransitPresented to 12th TRB Transportation Planning Applications Conference, Houston, TXBing Mei, P.E.Triangle Regional Model Service BureauITRE @ NCSUMay 19, 2009
Introduction • Initially developed in 2006 for creating and managing highway and transit networks for the Triangle Regional Model • Improved during the past couple of years • Extensively used in 2008 and 2009 for • 2035 Long Range Transportation Plan studies • 37 scenarios • Total 800+ highway projects and phases coded • 300+ ~ 600+ transit routes in each scenario • Regional Transit Vision Plan studies (multiple scenarios) • by Capital Area Metropolitan Planning Organization (CAMPO), Durham-Chapel Hill-Carrboro (DCHC) MPO, Triangle Transit (TT), NCDOT, and consultants
Goal • A highly interactive tool that improves network coding efficiency, especially for transit • If not handled properly, being interactive means being • user error prone • logic hole prone • challenged frequently by unthought-of situations • A highly interactive tool should • first of all, work & work correctly • be user-friendly and easy to use • be well balanced between flexibility and reliability • be well thought-out for all possible situations and hence robust • be able to capture, prevent, and/or handle user errors before they crash the system or cause problems later
System Structure • Two major components: • Highway network management • Project based • ONE universe highway network: • base year network, plus • ALL future year projects as a pool • A scenario network = base year network + projects selected from the pool • Transit network management • Specific scenario highway network based • Why not ONE single universe highway network based? • Does not exclude the use of the universe highway network as an option (turned out to be a great option for the Triangle Region) • Transit routes can be • Created from scratch • Revised from existing, or • Borrowed from other scenarios • A whole transit route system can be easily recreated after the background highway network has been significantly altered
Highway Management • Two subcomponents: • Project Tool: creating and managing highway projects • projects are basic building blocks for creating a scenario highway network • definition of projects (e.g. extension of I-540 from I-40 to NC 55) • project data management: • project ID • project description • project open to traffic time • predecessor and successor projects • road section attributes (e.g. #lanes, posted speed, median type, signal density, etc.) • special case: road closure
Highway Management (2) • Scenario Tool: creating and managing highway scenario networks • A scenario network = base year network + selected projects • Selection of projects: • From the universe project pool • manually one by one (or several by several) • by open to traffic time • From project list table(s) • by reading a project list defined in an external spreadsheet file • by inheriting projects from other scenarios • Use of the four approaches can be combined
Highway Tools Scenario Tools Project Tools
Before After Merge Split Re-align More complicated… Transit Management • The real challenging part! Why? • Highway project: one or multiple roadway sections are involved, but don’t have to be in sequence or even connected • Transit route: mostly multiple roadway sections are involved, and more importantly they must be connected to one another in sequence • Transit routes are usually represented as a series of highway sections in software packages • But the underlying highways change! • If a section is no longer part of a highway project, simply drop it and the project still has a valid representation in the software • Can we simply drop that section from a transit route? NO! • Furthermore, what about other changes:
Transit Management (2) • Two subcomponents: • One for creating transit routes and the route system • Create from scratch • Revise from existing, or • Borrow from other scenarios • GIS functionality is critical • Saves a huge amount of time than coding from scratch • One for re-creating route systems • When the underlying highway network has gone through significant editing • When borrowing a large number of transit routes from other transit route systems that already exist • When creating a subset of a transit route system with an altered highway network • GIS, GIS, and GIS!! • Hundreds of hours saved for CAMPO and DCHC LRTP modeling
Transit Tools Create Routes & Route System Re-create Route System
Acknowledgement • Good suggestions from TRM Service Bureau colleagues: • Chao Wang • Joe Huegy • Leta Huntsinger (DCHC MPO currently) • Others
Contact Info • Bing Mei: bmei@ncsu.edu