1. NYC DOT Open Source Routing
PgRouting with LION and CSCL

2. Welcome Joseph Miller Professional Services Engineer
Boundless provides geospatial tools and services for managing data and building applications.
Middle Tier Development and Integrator of fun projects including:
GeoServer, OpenLayers, GeoShape, GeoGig

3. Problem Statement
Goals
Assets
Research/Survey
Technologies
Architecture
Accomplishments...So Far
Lessons Learned and Next Steps
Future Steps

4. NYC DOT is responsible for over 6,000 miles of roadway and nearly 800 bridges along with the 24/7 operation of the Staten Island Ferry. They have more than 12,000 signalized intersections and over 300,000 streetlights.

5. Inefficiency NYC Truck Permitting
Large Vehicles Require Trip Specific “Overdimensional” permits
The permits specify the details of the route
Currently a manual, in-person process
Route Must Account For
Vehicle weight
Vehicle Height
Road conditions and closures

6. Overdimensional permits apply to trucks over 800 GVW
Specifics depend on routes, axle spacing, and vehicle configuration
100K+ Permits Issued Statewide Every Year

7. Goals Point to Point Routing Visualization Routing Around Barriers
Use designated truck routes
Address
POI
Lat/Long
Routing Around Barriers
Real/Near-Real-Time
Height Restrictions
Weight Restrictions
Turn Restrictions
Blockages
Visualization
Route Segments
Turn-By-Turn Directions

10. Assets LION/CSCL Topologically Complete (including z-levels)
Street Names
Truck Routes
POI

11. Survey Criteria Low or No Cost BYOD Flexible Performant
Low Cost of Integration

12. Tech Considered

13. Open Source Routing Machine
BSD License
C++ and LUA
OpenStreetMap

14. Why It Fit
Fast (Contraction Hierarchy Indexing)
Fast and easy install
Option to switch between cost profiles
Cost profiles are customizable using LUA scripts.
Supports partial contraction for quick updates when the data changes

15. Contraction Hierarchies
Illustrated very well here:
Routing graph preprocessed to “contract” intermediate nodes that are discovered to be parts of shortest paths

16. https://raw. githubusercontent. com/rodo/osrm-profiles/master/truck
speed_profile = { ["motorway"] = 90, ["motorway_link"] = 75, ["trunk"] = 85, ["trunk_link"] = 70, ["primary"] = 65, ["primary_link"] = 60, ["secondary"] = 55, ["secondary_link"] = 50, ["tertiary"] = 40, ["tertiary_link"] = 30, ["unclassified"] = 25, ["residential"] = 25, ["living_street"] = 10, ["service"] = 15, -- ["track"] = 5, ["ferry"] = 5, ["shuttle_train"] = 10, ["default"] = 10 } take_minimum_of_speeds = false obey_oneway = true obey_bollards = true use_restrictions = true ignore_areas = true -- future feature traffic_signal_penalty = 2 u_turn_penalty = 20
function node_function (node) local barrier = node.tags:Find("barrier") local access = Access.find_access_tag(node, access_tags_hierachy) local traffic_signal = node.tags:Find("highway") --flag node if it carries a traffic light if traffic_signal == "traffic_signals" then node.traffic_light = true; end -- parse access and barrier tags if access and access ~= "" then if access_tag_blacklist[access] then node.bollard = true end elseif barrier and barrier ~= "" then if barrier_whitelist[barrier] then return else node.bollard = true end end end

17. Challenges
OSM-centric, challenging to use custom model
Partial contraction still requires downtime
Partial contraction leads to performance degradation

18. Mapzen Turn-by-Turn/Valhalla
MIT License
C++
OpenStreetMap

19. Why It Fit
Fast and low memory footprint
Flexible storage model using THOR route tiles
Lots of Costing Models (profiles) and Costing Model Options
SIF allows for custom profiles that can be applied at run time with a minimal performance impact

20.
namespace { constexpr float kDefaultManeuverPenalty = 5.0f; // Seconds constexpr float kDefaultDestinationOnlyPenalty = 600.0f; // Seconds constexpr float kDefaultAlleyPenalty = 30.0f; // Seconds constexpr float kDefaultLowClassPenalty = 30.0f; // Seconds constexpr float kDefaultGateCost = 30.0f; // Seconds constexpr float kDefaultGatePenalty = 300.0f; // Seconds constexpr float kDefaultTollBoothCost = 15.0f; // Seconds constexpr float kDefaultTollBoothPenalty = 0.0f; // Seconds constexpr float kDefaultCountryCrossingCost = 600.0f; // Seconds constexpr float kDefaultCountryCrossingPenalty = 0.0f; // Seconds // Default turn costs constexpr float kTCStraight = 0.5f; constexpr float kTCSlight = 0.75f; constexpr float kTCFavorable = 1.0f; constexpr float kTCFavorableSharp = 1.5f; constexpr float kTCCrossing = 2.0f; constexpr float kTCUnfavorable = 2.5f; constexpr float kTCUnfavorableSharp = 3.5f; constexpr float kTCReverse = 5.0f;
/ Check if access is allowed at the specified node. bool TruckCost::Allowed(const baldr::NodeInfo* node) const { return (node->access() & kTruckAccess); } // Get the cost to traverse the edge in seconds Cost TruckCost::EdgeCost(const DirectedEdge* edge, const uint32_t density) const { float factor = density_factor_[density]; if (edge->truck_route() > 0) { factor *= kTruckRouteFactor; } float sec = 0.0f; if (edge->truck_speed() > 0) sec = (edge->length() * speedfactor_[edge->truck_speed()]); else sec = (edge->length() * speedfactor_[edge->speed()]); return { sec * factor, sec }; }

21. Challenges
SIF custom profiles require C++ code
Built around OSM data schema, not clear how to add data from custom schemas without transformation

22. GraphHopper https://graphhopper.com/ Apache License V2
Java
OpenStreetMap

23. Why It Fit
Very fast and low memory footprint in Speedup Mode (Contraction Hierarchy Indexing)
Very quick and easy install
Option to switch between cost profiles
Java API enables custom data models (extend the Reader class)
Java API enables on the fly traversal cost and turn restrictions (FlagEncoder classes)

24.
protected double getSpeed( OSMWay way ) { String highwayValue = way.getTag("highway"); Integer speed = defaultSpeedMap.get(highwayValue); if (speed == null) throw new IllegalStateException(toString() + ", no speed found for: " + highwayValue + ", tags: " + way); if (highwayValue.equals("track")) { String tt = way.getTag("tracktype"); if (!Helper.isEmpty(tt)) { Integer tInt = trackTypeSpeedMap.get(tt); if (tInt != null) speed = tInt; } } return speed; }
restrictions.addAll(Arrays.asList("motorcar", "motor_vehicle", "vehicle", "access")); restrictedValues.add("private"); restrictedValues.add("agricultural"); restrictedValues.add("forestry"); restrictedValues.add("no"); restrictedValues.add("restricted"); restrictedValues.add("delivery"); restrictedValues.add("military"); restrictedValues.add("emergency");

25. Challenges
Extending the Reader to read the LION schema would have been taken more time than we had.
Use of FlagEncoder dynamically is not compatible with CH Speedup Mode
Java codebase/API (for the custom stuff) presents challenge to .NET shop

26. pgRouting http://pgrouting.org/ GPL V2
C++

27. Why It Fit
Very simple data schema
Right place in the architecture
Straightforward to implement custom traversal costs and turn restrictions

28.
seq | node | edge | cost | 7 | 6 | | 8 | 7 | | 5 | 8 | | 6 | 11 | | 11 | 13 | | 12 | -1 | 0 (6 rows)
SELECT seq, id1 AS node, id2 AS edge, cost FROM pgr_trsp( 'SELECT id, source, target, cost FROM edge_table', , 12, false, false, 'SELECT to_cost, to_edge AS target_id, from_edge || coalesce('','' || via, '''') AS via_path FROM restrictions' );

29. Challenges
Slow
Spoken language driving directions not included
No REST or JavaScript API included

31. Technologies PgRouting PostGIS Spring Turn Restricted Shortest Path
Spatial Operators
Spatial Indices
Spring
REST Services
Leaflet
Basemap Display
Vector rendering of routes
Click UI

32. Driving Directions API

33. Turn-By-Turn Directions
Based on PostgreSQL functions developed by Stephen Woodbridge
Concepts explained:
reorder the direction of edge geometry so it flows from start to end
compare segment names so we can aggregate multiple adjacent segments with the same name into a single maneuver.
compute the turn angles between segments when we are making a turn
counting roundabout exits from our entrance point
identify a via point
check for some degenerate cases like the whole route is on a single segment

34. Columbus Circle is one of only a half dozen traffic circles/roundabouts in NYC. It serves 60K+ vehicles a day.

35. Basic Geocoding Reverse Geocode Forward Geocode
<-> Operator Query for nearest segment
St_line_locate_point for percentage
Forward Geocode
Parse Address using code from JGeocoder (
Use street name and address ranges to find the correct segment and derive percentage

36. Service Wrapper Simple Spring Boot/Spring Web MVC implementation
Direct JDBC calls
Easily ported to future ASP.NET/ADO.NET implementation

37. Accomplishments...So Far
Inputs
Addresses
Truck Route Places
Outputs
Turn-By-Turn Directions
Route Segment Map Display
Segment Metadata
Topology Connectivity
Forward and Reverse Costs
Truck Route Identity
Route Creation
Truck Route Segment Preference
Turn Restrictions
Height and Weight Restrictions

40. Accomplishments...So Far
String ddsql = "select (dd).instruction, (dd).geojson,(dd).dist_meters/ as dist_miles
from (select imt_drivingDirections(ST_Line_Interpolate_Point(r1.wkb_geometry_ll_simple,"+pct1+"), ST_Line_Interpolate_Point(r2.wkb_geometry_ll_simple,"+pct2+"),eng',
'SELECT seq as gid, source, target, street as name, shape_length/ as distance,
(shape_length*.6)::integer as time, wkb_geometry_ll_simple as the_geom
FROM pgr_trsp(
''SELECT segmentid::integer as id, source, target,
createCostSQL(useTruckRoutes)
createReverseCostSQL(useTruckRoutes)
''"+segmentid1+"''::integer, "+pct1+",''"+segmentid2+"''::integer,"+pct2+", true, true,
''SELECT -1::float as to_cost, t_segmentid::integer AS target_id,
f_segmentid::text AS via_path
FROM turnrestriction''
)as di
left JOIN lion pt ON di.id2 = pt.segmentid::integer order by seq') as dd
from lion as r1, lion as r2
where r1.segmentid = '"+segmentid1+"' and r2.segmentid = '"+segmentid2+"' ) AS foo;

41. Accomplishments...So Far
private String createCostSQL(boolean useTruckRoutes){
String base =" (case when trafdir=''''A'''' THEN -1
WHEN trafdir='''' '''' THEN -1
WHEN trafdir=''''P'''' THEN -1
WHEN segmentid::integer in(SELECT segmentid FROM physicalrestrictions_populated) THEN -1 ";
String basecost = base + "ELSE shape_length END)::float as cost,";
if(useTruckRoutes)
basecost = base+"ELSE CASE
WHEN segmentid in(SELECT segmentid from all_truck_routes_nyc_lion14a) THEN 0.1 ELSE shape_length END END)::float as cost,";
return basecost; }
Accomplishments...So Far

42. Future Steps Truck Class UI to select
Traversal cost/barriers matched to class
By weight
By Height
By Cargo

43. Future Steps Improved Base Segment Traversal Cost Calculations
Speed Limits
Historical Traffic Data
Web-Based Barrier and Cost Management
Map-based barrier creation and editing
Visual cues to identify data gaps
Potential Height and Weight Restriction Gaps
Topology Management

44. Future Steps Route Calculation Performance
Database query optimization
Load balanced hardware (pgPool?, Partitioning?)
Clean up and transformation of multi-line geometries to single line features
Directed Segment Styling (arrows)
Integration into the Permitting Process