Inventorying Linear Assets From Field to GIS to Database
Think . . . Spatially
Inventorying Linear Assets From Field to GIS to Database
HILLSBOROUGH COUNTY, FLORIDA Tampa
North North Subdivision Development Thru January 2007
Since 1986, 1986, about about 30 30 C-L C-L miles miles of of Since new roads roads have have been been added added per per year year new
A Growing County Lots of Point Assets • • • • • • • •
> 96,800 Traffic Signs > 25,000 Inlets > 19,000 Sidewalk Ramps > 17,000 Intersections Nearly 5,000 Stormwater Manholes > 1,300 Pedestrian Crossings > 250 Bridges > 190 Railroad Crossings
A Growing County Lots L-O-N-G Assets, Too • • • • • • •
> 6,700 Miles of Traffic Lanes Nearly 4,000 Miles of Pavement Striping > 3,200 Miles of Shoulders > 2,600 Miles of Curbs > 2,200 Miles of Sidewalks > 170 Miles of Dividers Nearly 30 Miles of Guard Rails
TOC • Overview • Linear Referencing Concepts • Field Data Collection Protocols and Software • Route Processing Tools for Postprocessing Field Data • Best-Practices for GPS, Range-finding and Field Data Collection • The Asset Management System
Overview • Data Collection Using ArcGIS Engine and ArcPad • Post Processing Using ArcGIS • Transferring Data to Asset Management System Using Various Software Tools (Visual Basic)
Ways to Collect Linear Features • Digitize using high-quality aerial photos • Collect a series of points, or “vertices,” along the feature • If paralleling other linear features, such as a street centerline (C-L), then simply collect the start and end points and take advantage of linear referencing
What We Wanted To Do
What Is Linear Referencing? • Sometimes a picture can save on words
Routes and Linear Referencing (Sidewalks)
12 34 5.0 0
12345.00R 001010
12345.00 L 001000
TO
Offset (to right) -Offset (to left) 12345.00 R 001000
FROM
Linear Referencing Concepts • Takes Advantage of ESRI’s Dynamic Segmentation Support • Utilizes a Linear Referencing Route System • Converting Field-collected “Points” to Linear Features
Why Linear Referencing? Real Purty • Here’s Another Picture
Speed Limits
Measuring Along Routes
There Thereare aretwo tworoutes routes (04899.00 (04899.00and and04904.00) 04904.00) nearby nearbyand andtwo twodifferent different mileposts. mileposts. This Thisambiguity ambiguitycan can be beresolved resolvedby byindicating indicatingwhich which route routeID IDto touse. use. There Thereisisonly onlyone oneroute route (04904.00) (04904.00)nearby nearbyand andno no ambiguity. ambiguity.
Measuring Along Routes Cherry CherryRose RoseCir Cir(05827.00) (05827.00)starts startsat at the intersection with Reflections Blvd. the intersection with Reflections Blvd. We Wealready alreadyknow knowabout aboutthis thisambiguity. ambiguity.
05827.00 .023 Mi. 15.00 Ft 05827.00 .316 Mi. -15.00 Ft
AApoint pointat atthe thecorner, corner,for foraasidewalk sidewalk end-point, let’s say, introduces end-point, let’s say, introducesaanew new kind kindof ofambiguity. ambiguity. The Thepoint pointcan canbe beeither eitheron onthe theright rightof of the route (15 Ft) at the smaller milepost the route (15 Ft) at the smaller milepost (.023 (.023Mi.), Mi.),or oron onthe theleft left(-15 (-15Ft) Ft)at atthe the higher milepost (.316 Mi.). Either could higher milepost (.316 Mi.). Either could be becorrect. correct.
Cherry CherryRose RoseCir Cir(05827.00) (05827.00)intersects intersects with itself about 100 feet (.023 with itself about 100 feet (.023Mi.) Mi.) south southof ofReflections ReflectionsBlvd. Blvd. The Theroute routethen thenincreases increasesfrom fromthe the intersection in the clock-wise direction intersection in the clock-wise direction all allthe theway wayaround aroundthe theloop loopand andback backto to the intersection. the intersection.
Field Data Collection Concept
23
Field Data Collection Software
Street C-L Points
Manholes School Zone Start and End
Field Data Collection Software Two Two linear linear features features are are already already being being collected collected (Curbs (Curbs and and Sidewalks) Sidewalks) as as indicated indicated by by the the red red boxes boxes around around the the icons. icons.
THRU lanes have end points at the center of the inte rsection(s) they go “thru” or into
Dividers Guard Rails Lane Counts
Field Data Collection of Pavement Markings Long-line Pavement Markings are collected for each side of a street and includes all markings from the edge of the road to its centerline or divider. Centerlines are counted on the first side of the street that is inventoried. Markings have end points at the edge of the intersection(s) they go into
One Way Pavement Markings Road Widths School Zones Shoulders Sidewalk Handrails Sidewalks
Changes in Markings occur where any new line starts or a line ends
Speed Limit Zones Surface Types
BIKE LANE DIVIDER LANE COUNT MARKINGS SIDWK HNDRAIL(c) SIDWK HNDRAIL(n) SURFACE TYPE __ __ _X _X __ __ __
__ BIKE LANE __ DIVIDER _X SIDWK HNDRAIL(c) __ SURFACE TYPE
__ CURB __ LANE COUNT _X MARKINGS _X SIDEWALK
__ __ __ _X __
Curbs
TURN lanes have end points where they reach full-width and at the edge of the intersection they turn into
BIKE LANE __ CURB DIVIDER _X LANE COUNT SIDWK HNDRAIL(c) _X MARKINGS SIDWK HNDRAIL (n) __ SIDEWALK SURFACE TYPE
CURB LANE COUNT MARKINGS SIDEWALK SIDWK HNDRAIL(c) SIDWK HNDRAIL(n) __ __ __ __ _X _X
Bike Lanes
THE MANY POINT FEATURES DEPICTED WOULD ALSO BE COLLECTED AS THEY ARE ENCOUNTERED, BUT THIS IS NOT INDICATED BY THIS EXAMPLE.
Hillsborough County Public Works Department Field Data Collection Protocols For Transportation Assets July 21, 2006
_ X C URB __ DIVI DER __ LAN E COUN T __ MARKIN GS __ SIDEWALK __ SIDWK HN DRAIL (c) __ SIDWK HN DRAIL (n ) __ SURFACE TYP E (not a compl ete li st of all l inea r fea tures)
Although a curb usually “drops down” at things like driveways, the curb is considered to be continuous across driveways. Typically, a curb extends for the full length of the block of a street. This is not always the case, but as a rule, curbs will have start and end at of Lane Counts Field Datapoints Collection Lane counts are collected for each side of a street intersections, as in the illustration, above. and includes all lanes from the edge of the road to its centerline or divider Another illustration of determining endpoints for curbs is shown for a cul-de-sac, below.
__ CURB _ X DIVIDER __ LANE COUNT __ MARKINGS __ SIDEWALK __ BIKE LANE __ CURB _X SIDEWALK _X DIVIDER __ SIDWK HNDRAIL(c) __ SIDWK HNDRAIL(n) __ LANE COUNT _X MARKINGS __ SURFACE TYPE __ SIDEWALK __ BIKE LANE _ X DIVIDER __ BIKE LANE __ SIDWK HNDRAIL(c) _ X DIVIDER _ X LANE COUNT __ SIDWK HNDRAIL(n) _ X MARKINGS __ SURFACE TYPE __ SIDE WALK __ BIKE LANE __ SIDW K HNDRAIL(c) __ SIDW K HNDRAIL(n) __ DIVIDER __ SUR FACE TYPE _ X MARKINGS (as more linear feature s are __ SIDWK HNDRAIL(c) started, t he list of item s that __ SIDWK HNDRAIL(n) can be s tarted, shortens) __ SURFACE TYPE __ BIKE LANE
Locating Curb Endpoints at Intersections Use the middle of the Return (the curved corner)
Example of identifying the end-points of several linear features in parallel: NOTE the vertical red lines indicate the location for the start or end points.
Curb Endpoints
Street Centerline
Curb Endpoints
Street Centerline
Street Centerline
Street Centerline
Field Data Collection of Multiple Linear Asssets
Intersec tion
Intersec tion
Intersec tion
Curb Endpoints
_X CURB _X LANE COUNT
Field Data Collection Protocols and Software (Linear Features)
Meanwhile, Back in the Office
Meanwhile, Back in the Office
FROM_MP
TO_MP
Meanwhile, Back in the Office
Route Processing Steps-Concept Using a Personal GeoDatabase . . .
Select Points
Run Route Location Wizard
Press Toolbar Button
Press Button in Access
A custom button to activate Access®
Form w/ button to activate update query in Access®
Close Access
Refresh GIS View
Voila!!
Route Processing Toolbar Add Events Export to Shape
Create Routes from C-L GIS
Edit Existing Routes + extend from start + extend from end + shorten from start + shorten from end
Process field-collected Point-pairs and Create Linear Events from Them Determine Measure (Milepost) and Distance (Offset) for Point Data, Like Traffic Signs
Route Processing Toolbar
Post Processing Software
Field Data Collection Tools and Best-Practices • • • •
Importance of a Good Centerline GPS (Global Positioning System) Laser Range Finding Database Management
A Good C-L GIS Is Essential
A Good C-L GIS Is Essential Two Two pairs pairs of of end end points points with with PointPairIDs PointPairIDs of of 84 84 –– Sidewalk, Sidewalk, and and 87 87 –– Curb Curb
Erroneous C-L
Even Even though though the the C-Ls C-Ls are are only only 99 feet feet apart, apart, better better placement placement of of itit changes changes the the side side of of the the road road that that the the curb curb and and sidewalk sidewalk are are on. on.
Field-corrected C-L
A Good C-L GIS Is Essential • For this reason, collecting points along centerlines of streets is now part of our field data collection process. • Points are collected at intersections, geometry changes and at points along curves. • Back in the office, the C-L geometry is adjusted to “snap” to the field collected points.
GPS Issues • GPS (Global Positioning System) is neither magic nor fool-proof • Used carelessly, poor data will result • Know the short-comings and minimize them as much as possible • Then perform quality control checks on any data collected using GPS
GPS Issues (cont’d) • Not all GPS equipment are created equal • Satellites are constantly moving and their “geometry” constantly changing – No two reads at the same location will be equal – Some conditions better than others, e.g., PDOP (Position Dilution of Precision) values
• Satellite signals can “bounce” off nearby objects and cause errors
GPS Best-practices • Cheaper is NOT better • Use equipment/software that can control quality (and report it) • WAAS (Wide Area Augmentation System) should not be relied on • Set a PDOP Mask of
Inventorying Linear Assets From Field to GIS to Database
HILLSBOROUGH COUNTY, FLORIDA Tampa
North North Subdivision Development Thru January 2007
Since 1986, 1986, about about 30 30 C-L C-L miles miles of of Since new roads roads have have been been added added per per year year new
A Growing County Lots of Point Assets • • • • • • • •
> 96,800 Traffic Signs > 25,000 Inlets > 19,000 Sidewalk Ramps > 17,000 Intersections Nearly 5,000 Stormwater Manholes > 1,300 Pedestrian Crossings > 250 Bridges > 190 Railroad Crossings
A Growing County Lots L-O-N-G Assets, Too • • • • • • •
> 6,700 Miles of Traffic Lanes Nearly 4,000 Miles of Pavement Striping > 3,200 Miles of Shoulders > 2,600 Miles of Curbs > 2,200 Miles of Sidewalks > 170 Miles of Dividers Nearly 30 Miles of Guard Rails
TOC • Overview • Linear Referencing Concepts • Field Data Collection Protocols and Software • Route Processing Tools for Postprocessing Field Data • Best-Practices for GPS, Range-finding and Field Data Collection • The Asset Management System
Overview • Data Collection Using ArcGIS Engine and ArcPad • Post Processing Using ArcGIS • Transferring Data to Asset Management System Using Various Software Tools (Visual Basic)
Ways to Collect Linear Features • Digitize using high-quality aerial photos • Collect a series of points, or “vertices,” along the feature • If paralleling other linear features, such as a street centerline (C-L), then simply collect the start and end points and take advantage of linear referencing
What We Wanted To Do
What Is Linear Referencing? • Sometimes a picture can save on words
Routes and Linear Referencing (Sidewalks)
12 34 5.0 0
12345.00R 001010
12345.00 L 001000
TO
Offset (to right) -Offset (to left) 12345.00 R 001000
FROM
Linear Referencing Concepts • Takes Advantage of ESRI’s Dynamic Segmentation Support • Utilizes a Linear Referencing Route System • Converting Field-collected “Points” to Linear Features
Why Linear Referencing? Real Purty • Here’s Another Picture
Speed Limits
Measuring Along Routes
There Thereare aretwo tworoutes routes (04899.00 (04899.00and and04904.00) 04904.00) nearby nearbyand andtwo twodifferent different mileposts. mileposts. This Thisambiguity ambiguitycan can be beresolved resolvedby byindicating indicatingwhich which route routeID IDto touse. use. There Thereisisonly onlyone oneroute route (04904.00) (04904.00)nearby nearbyand andno no ambiguity. ambiguity.
Measuring Along Routes Cherry CherryRose RoseCir Cir(05827.00) (05827.00)starts startsat at the intersection with Reflections Blvd. the intersection with Reflections Blvd. We Wealready alreadyknow knowabout aboutthis thisambiguity. ambiguity.
05827.00 .023 Mi. 15.00 Ft 05827.00 .316 Mi. -15.00 Ft
AApoint pointat atthe thecorner, corner,for foraasidewalk sidewalk end-point, let’s say, introduces end-point, let’s say, introducesaanew new kind kindof ofambiguity. ambiguity. The Thepoint pointcan canbe beeither eitheron onthe theright rightof of the route (15 Ft) at the smaller milepost the route (15 Ft) at the smaller milepost (.023 (.023Mi.), Mi.),or oron onthe theleft left(-15 (-15Ft) Ft)at atthe the higher milepost (.316 Mi.). Either could higher milepost (.316 Mi.). Either could be becorrect. correct.
Cherry CherryRose RoseCir Cir(05827.00) (05827.00)intersects intersects with itself about 100 feet (.023 with itself about 100 feet (.023Mi.) Mi.) south southof ofReflections ReflectionsBlvd. Blvd. The Theroute routethen thenincreases increasesfrom fromthe the intersection in the clock-wise direction intersection in the clock-wise direction all allthe theway wayaround aroundthe theloop loopand andback backto to the intersection. the intersection.
Field Data Collection Concept
23
Field Data Collection Software
Street C-L Points
Manholes School Zone Start and End
Field Data Collection Software Two Two linear linear features features are are already already being being collected collected (Curbs (Curbs and and Sidewalks) Sidewalks) as as indicated indicated by by the the red red boxes boxes around around the the icons. icons.
THRU lanes have end points at the center of the inte rsection(s) they go “thru” or into
Dividers Guard Rails Lane Counts
Field Data Collection of Pavement Markings Long-line Pavement Markings are collected for each side of a street and includes all markings from the edge of the road to its centerline or divider. Centerlines are counted on the first side of the street that is inventoried. Markings have end points at the edge of the intersection(s) they go into
One Way Pavement Markings Road Widths School Zones Shoulders Sidewalk Handrails Sidewalks
Changes in Markings occur where any new line starts or a line ends
Speed Limit Zones Surface Types
BIKE LANE DIVIDER LANE COUNT MARKINGS SIDWK HNDRAIL(c) SIDWK HNDRAIL(n) SURFACE TYPE __ __ _X _X __ __ __
__ BIKE LANE __ DIVIDER _X SIDWK HNDRAIL(c) __ SURFACE TYPE
__ CURB __ LANE COUNT _X MARKINGS _X SIDEWALK
__ __ __ _X __
Curbs
TURN lanes have end points where they reach full-width and at the edge of the intersection they turn into
BIKE LANE __ CURB DIVIDER _X LANE COUNT SIDWK HNDRAIL(c) _X MARKINGS SIDWK HNDRAIL (n) __ SIDEWALK SURFACE TYPE
CURB LANE COUNT MARKINGS SIDEWALK SIDWK HNDRAIL(c) SIDWK HNDRAIL(n) __ __ __ __ _X _X
Bike Lanes
THE MANY POINT FEATURES DEPICTED WOULD ALSO BE COLLECTED AS THEY ARE ENCOUNTERED, BUT THIS IS NOT INDICATED BY THIS EXAMPLE.
Hillsborough County Public Works Department Field Data Collection Protocols For Transportation Assets July 21, 2006
_ X C URB __ DIVI DER __ LAN E COUN T __ MARKIN GS __ SIDEWALK __ SIDWK HN DRAIL (c) __ SIDWK HN DRAIL (n ) __ SURFACE TYP E (not a compl ete li st of all l inea r fea tures)
Although a curb usually “drops down” at things like driveways, the curb is considered to be continuous across driveways. Typically, a curb extends for the full length of the block of a street. This is not always the case, but as a rule, curbs will have start and end at of Lane Counts Field Datapoints Collection Lane counts are collected for each side of a street intersections, as in the illustration, above. and includes all lanes from the edge of the road to its centerline or divider Another illustration of determining endpoints for curbs is shown for a cul-de-sac, below.
__ CURB _ X DIVIDER __ LANE COUNT __ MARKINGS __ SIDEWALK __ BIKE LANE __ CURB _X SIDEWALK _X DIVIDER __ SIDWK HNDRAIL(c) __ SIDWK HNDRAIL(n) __ LANE COUNT _X MARKINGS __ SURFACE TYPE __ SIDEWALK __ BIKE LANE _ X DIVIDER __ BIKE LANE __ SIDWK HNDRAIL(c) _ X DIVIDER _ X LANE COUNT __ SIDWK HNDRAIL(n) _ X MARKINGS __ SURFACE TYPE __ SIDE WALK __ BIKE LANE __ SIDW K HNDRAIL(c) __ SIDW K HNDRAIL(n) __ DIVIDER __ SUR FACE TYPE _ X MARKINGS (as more linear feature s are __ SIDWK HNDRAIL(c) started, t he list of item s that __ SIDWK HNDRAIL(n) can be s tarted, shortens) __ SURFACE TYPE __ BIKE LANE
Locating Curb Endpoints at Intersections Use the middle of the Return (the curved corner)
Example of identifying the end-points of several linear features in parallel: NOTE the vertical red lines indicate the location for the start or end points.
Curb Endpoints
Street Centerline
Curb Endpoints
Street Centerline
Street Centerline
Street Centerline
Field Data Collection of Multiple Linear Asssets
Intersec tion
Intersec tion
Intersec tion
Curb Endpoints
_X CURB _X LANE COUNT
Field Data Collection Protocols and Software (Linear Features)
Meanwhile, Back in the Office
Meanwhile, Back in the Office
FROM_MP
TO_MP
Meanwhile, Back in the Office
Route Processing Steps-Concept Using a Personal GeoDatabase . . .
Select Points
Run Route Location Wizard
Press Toolbar Button
Press Button in Access
A custom button to activate Access®
Form w/ button to activate update query in Access®
Close Access
Refresh GIS View
Voila!!
Route Processing Toolbar Add Events Export to Shape
Create Routes from C-L GIS
Edit Existing Routes + extend from start + extend from end + shorten from start + shorten from end
Process field-collected Point-pairs and Create Linear Events from Them Determine Measure (Milepost) and Distance (Offset) for Point Data, Like Traffic Signs
Route Processing Toolbar
Post Processing Software
Field Data Collection Tools and Best-Practices • • • •
Importance of a Good Centerline GPS (Global Positioning System) Laser Range Finding Database Management
A Good C-L GIS Is Essential
A Good C-L GIS Is Essential Two Two pairs pairs of of end end points points with with PointPairIDs PointPairIDs of of 84 84 –– Sidewalk, Sidewalk, and and 87 87 –– Curb Curb
Erroneous C-L
Even Even though though the the C-Ls C-Ls are are only only 99 feet feet apart, apart, better better placement placement of of itit changes changes the the side side of of the the road road that that the the curb curb and and sidewalk sidewalk are are on. on.
Field-corrected C-L
A Good C-L GIS Is Essential • For this reason, collecting points along centerlines of streets is now part of our field data collection process. • Points are collected at intersections, geometry changes and at points along curves. • Back in the office, the C-L geometry is adjusted to “snap” to the field collected points.
GPS Issues • GPS (Global Positioning System) is neither magic nor fool-proof • Used carelessly, poor data will result • Know the short-comings and minimize them as much as possible • Then perform quality control checks on any data collected using GPS
GPS Issues (cont’d) • Not all GPS equipment are created equal • Satellites are constantly moving and their “geometry” constantly changing – No two reads at the same location will be equal – Some conditions better than others, e.g., PDOP (Position Dilution of Precision) values
• Satellite signals can “bounce” off nearby objects and cause errors
GPS Best-practices • Cheaper is NOT better • Use equipment/software that can control quality (and report it) • WAAS (Wide Area Augmentation System) should not be relied on • Set a PDOP Mask of
