Download - Using Utah's Linear Referencing GIS Layer: SGID93.Transportation.UDOTRoutes_LRS

4/7/2011 Thomas McMurtry

UsingUtah’s LRS

Thomas McMurtry

InterPlan

Bert Granberg

AGRC

What is an LRS

Linear Referencing System Route Definition

System Standards Route Names, IDs Ordered Road Segments Calibration Points {Start, Intermediate(s), End}

Physical monuments (mileposts, exit nbrs)

Linear Diagrams (1D)

Digital Geographic Base Reference (2D & 3D)

PolylineM Feature Class (x,y,m(easure) coordinates)

Why LRS?• Provides a Common Geometric Base• Simple geometry maintained in one place Events (as table rows, but references RT_ID + MP)

Point: Overhead sign 0015P 306.381

Line: Asphalt pavement overlay, 0210P 7.982 to 12.119 (lane 1)

– Think about lanes on I-15

• Analytical Advantages– Many ‘spatial’ operations are done in 1

dimension

Statewide Centerline Goals:

Accessible, Valued Public Resource

Currency:– Statewide roads published update every 2 months

Functionality:•Cartographic Base Map Support•Inventory (funding, jurisdiction, surface, etc)•Address Matching

– Street Address & Route/Milepost

•Routing Solutions

Statewide Centerline Goals:

Accessible, Valued Public Resource

Currency:– Statewide roads published update every 2 months

Functionality:•Cartographic Base Map Support•Inventory (funding, jurisdiction, surface, etc)•Address Matching

– Street Address & Route/Milepost

•Routing Solutions•Linear Referencing Base

– Adds Complexity but makes Enterprise Sense!!!

Linear Referencing System

• How it gets built– Statewide road, ramp & collector features:

• Connectivity, Alignment, Geometric Depiction

• DOT_RTNAME Route ID

• DOT_RTPART Part Number, for multipart routes

– Merge road features route features

– Calibration points• All part end points

• Intermediate points, about every 5-10 miles

Building Utah State Route 137

1. SELECT Participating Centerlines

2. ATTRIBUTE Road Features w/ RtName & RtPart_Nbr

0137PPart 1

0137PPart 2

0137PPart 3

3. MERGE Road Features Into Route Parts

0137PPart 1

0137PPart 2

0137PPart 3

4. CALIBRATE Route M Coordinates at Endpoints

2.3148.801

5. ADD INTERMEDIATE CALIBRATION Where Needed

6. MERGE Parts Into Single PolylineM Feature

6. MERGE Parts Into Single PolylineM Feature

7. QA

8. DERIVE Additional Products:

• Milepost Points (events!)

• Milepost Ranges on Road Features

•Integrated Highway & Local Data•Mileposts,•Exit Numbers,•Ramp IDS (not shown)

Happier Response Community


“P”

Nor

thbo

und

Mile

post

s 0

- 400“N

” S

outh

boun

d

Mile

post

s 0

- 400

“X”

So

uth

bo

un

d

Mil

epo

sts

400

- 0P, N, & X

• ‘P’ositive direction routes exist for all highways, measures increase in northbound or eastbound direction.

• ‘N’egative exist only for divided highway sections and depict the southbound or westbound directions

– Measures for Interstate N routes are in DRIVEN, not mileposted direction, as this is how UDOT inventories features on these routes

– For interstates, X route measures are according to physical mileposts in the negative direction (this is how they are common referenced outside of UDOT)


Agenda

– Tools– Points

• Making a point route event• Locating features along a route

– Segments• Making a segment route event• Overlay multiple route events


Tools

• Utah State Routes created by UDOT and AGRC

• ArcToolbox includes LRS tools as defalt

• Make sure that the routes functions are available

• P, N, & X


Point Data

• Make Route Event Layer– Working with tables

– Adding Crash Locations


LRS Table

• Remember Route Identifier is the LABEL column


Crash Table

• Use “=concatenate” in excel to create a label columnCRASH_ID Route Dir Label MILEPOINT CRASH_DATE CITY FIRST_HARM

10292727.000000 0023 P 0023P 5.900 7/13/2008 2510292435.000000 0023 P 0023P 1.200 7/21/2008 2510296580.000000 0023 P 0023P 5.920 4/10/2008 710112327.000000 0023 P 0023P 16.300 2/24/2008 CACHE JUNCTION 8810291643.000000 0023 P 0023P 11.200 1/30/2008 8810296647.000000 0023 P 0023P 2.300 4/9/2008 5710292252.000000 0023 P 0023P 5.920 7/27/2008 2510295504.000000 0023 P 0023P 2.600 5/3/2008 3110295687.000000 0023 P 0023P 2.400 4/29/2008 3910285663.000000 0023 P 0023P 15.600 12/19/2008 2510287125.000000 0023 P 0023P 5.040 11/28/2008 2510289947.000000 0023 P 0023P 6.100 9/23/2008 2510287713.000000 0023 P 0023P 3.100 11/13/2008 2510287673.000000 0023 P 0023P 19.170 11/14/2008 2510293079.000000 0023 P 0023P 5.920 7/4/2008 20


Example


Point Data

• Locate Features along a route– USTM Nodes– Intersection MPs


Example


Example

• Output Table

• MEAS is the measure of the milepost along the route


Example


Final Product


Segment Data

• Make Route Event Layer

• Must have begin and end MP

• UDOT segments– Crash Segments– Traffic Volume Segments– Travel Model Segments– Maintenance Segments


Example


Example

• Used to calculated expected crash rates

• Used for identifying top 5 %• Used for prioritization


Segment Data

• Overlay Route Events – Combine multiple

segment breaks


Example


Example

• Creates a table with segments broken by all possible breaks


Example

• Creates a table


Value of LRS Tools

• Save Time• Accurately map referenced data• Accurately reference mapped data• Link data from multiple sources to one

data point• Create new valuable products

• Only State Routes


Value of LRS Tools


Lessons Learned

• There are some work arounds– Requires database work

• I typically don’t get the results I want on the first try

• Some need to verify Mileposts

• Break large data sets up


Questions?

• Bert Granberg – [email protected]• Thomas McMurtry – [email protected]

Thank You

mailto:[email protected]

mailto:[email protected]