Managing Networks

A GIS & Project-Based Network Management System for Highways and Transit

Presented to 12th TRB Transportation Planning Applications Conference, Houston, TX

Bing Mei, P.E.Triangle Regional Model Service BureauITRE @ NCSU

May 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

Project Tools

Scenario Tools

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

Before

After

Split MergeRe-align More complicated…

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

Warning Message Examples

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

Thanks!