Expediting Nevada DOT s Crash Analysis through a Multilevel Linear Referencing System Session 6.3 Crashes

Transcription

1 Expediting Nevada DOT s Crash Analysis through a Multilevel Linear Referencing System Session 6.3 Crashes Grahame Ross, Nevada Department of Transportation Wednesday, April 18, 2012 Insert Company Logo Here

2 Overview Demographics of Nevada Mission/SMS project Goals Business Drivers MLLRS Design NDOT MLLRS Design Workflows Production Schedule Production Layers Issues Benefits Conclusion 2

3 Nevada Demographics Area - 7 th in the US in size: Total 110,567 mi 2 (286,367 km2) Width 322 mi (519 km) Length 490 mi (788 km) 5 of 20 largest counties in US Elevation- average elevation is 5,499 ft (1,676 m): Highest point (Boundary Peak) 13,140 ft (4,005 m) Lowest point (Colorado River) 479 ft (146 m) Population - 35th in US and 9 th least densely populated) Total 2,723,322 Las Vegas Metro 1,951,269 Reno/Sparks 315,475 Carson City 55,274 Highway System and Crashes State System Miles 5,384 County System Miles 31,000+ Crashes yearly under 50,000 (approximate) Geographic Area (South) Geographic Area (North) 3

4 Nevada Demographics 84% of population in 2 geographic areas with 90% of total crashes in those areas- majority of NDOT Safety Engineering s focus. 4

5 Mission- SMS project Goals Maintain current/accurate crash database of Nevada public roads Approximately 50,000 crashes annually Database contains 17 years of data ( ) Disseminate information statewide for improving highway safety Coordinate with other public safety agencies statewide Provide crash data/mitigation recommendations to NDOT roadway designers and engineering consultants Manage Highway Safety Improvement Program (HSIP) Analyze crash data to identify high crash locations Program and design safety projects SAFETEA-LU Reporting Requirements Safety programs data driven 5

6 Business Drivers Location transformation between different LRM s Location transformation on different geometric centerlines Naming/Standardization Event stability Time required to locate crashes Accuracy locating crashes Accessibility for decision support 6

7 Multilevel Linear Referencing System (MLRS) An MLRS supports the following: Multiple LRM s Multiple network/geometric representations A linear datum Transformation among LRM s An MLRS is supported by a robust data model 7

8 System Platform Hardware Powerful Desktop Systems Good Network Powerful Oracle Server Software GeoMedia Professional Fusion Transaction Manager Transportation Manager LRS metadata Database utilities Metadata tied into Oracle Oracle Workspace Manager Oracle Spatial 8

9 NDOT MLRS Design NDOT MLRS Design Multiple events Crashes, Mileposts Functional Classifications, Guardrail Multiple LRMs County cumulative Milepost index State cumulative Multiple geometries State network 4,500 features County network 173,000 features 9

10 NDOT MLRS Design EVENTS CRASHES FUNCTIONAL CLASSIFICATION GUARDRAIL LRMs CC LRM MAINT MI_LRM MAINT SC LRM MAINT DATUM TO LRM SC DL XREF CC DL XREF DATUM DATUM GEOMETRY TO DATUM SDS GD XREF CDS GD XREF GEOMETRY State Geom (SDS) County Geom (CDS) 10

11 Maintenance Workflows Automated LRS workflows crucial to success of crash analysis Replacements - Wholesale change of county data Geometry/connectivity validation Minimal attribute validation Bulk load of data Recalibration of LRS Updates - Additions, geometric or attribute changes to roads Minimal attribute validation Change detection Geometric additions/changes Attribute changes Geometry/connectivity validation Recalibration of LRS Interactive conflation Bulk load of new data Continuous data cleaning Issue tracker system Route Network Technical Group (RNTG) established to discuss effects of changes NDOT divisions affected by changes. 11

12 Change Detection Process 12

13 Production Schedule State-wide update completed every 2 years Large Counties, Mature GIS Clark Quarterly Washoe Semi-annual Medium Counties, Mature GIS Carson City Yearly Douglas County Yearly Small Counties, Differing level of GIS activity 13 other counties Bi-yearly 13

14 Production Layers LRM s County Cumulative, County Data Set (CC CDS) State Cumulative, County Data Set (SC CDS) State Cumulative, State Data Set (SC SDS) Milepost Index Intersection Objects Current Intersection Markers Current Intersection Features Milepost Markers 5 Year Crash Data 14

15 Challenges Specialized Workforce Oracle DBA familiar with Transaction Manager and Spatial Skilled GeoMedia user Project started with beta software Some instabilities and processing time Resolved in subsequent releases Data load to Oracle resets metadata Measure fields set precision 3 after load Oracle resets precision to 6 Intergraph aware of the problem Oracle to GeoMedia/ESRI number format Oracle stores numbers as a floating point Intergraph and ESRI software store as a fixed point Creates issues when wanting to do a spatial intersection Keeping SDS and CDS synchronized and calibrated 15

16 Benefits Increased reliability in locating crashes throughout the state No painful LRM conversions Increased throughput for safety analysis Aides in overall safety planning More comprehensive statewide LRS Data shared with local agencies uses same map and displays uniformly Local agency maintains the currency and accuracy of local road network 16

17 Conclusion The benefits of a Multi-level LRS come with a cost Data model more complicated Maintenance more complicated Edits to one layer has repercussions on other layers Special data maintenance tools help to simplify the process NDOT has better understanding of crash factors Shorten the time to devise mitigation strategies Safer roads for the traveling public 17

18 QUESTIONS