CADRE NAV08Presentation November2008 Tim Thornton Smartcom - - PowerPoint PPT Presentation

Slide 1 CADRE NAV08

CADRE
 
•
 NAV08
Presentation


November
2008


Tim Thornton Smartcom Software tt@smartcomsoftware.com

CADRE

NAV08

Slide 2

Congestion
 Avoidance
 Dynamic
 Routing
 Engine


Vehicle routing and traffic speed models for the real world

CADRE

NAV08

Slide 3

System
Overview


CADRE

NAV08

Slide 4

The
Congestion
Problem 


CADRE

NAV08

Slide 5

How
To
Tackle
Congestion 


• Build more roads
• Reduce use of vehicles on the roads
• More use of roads at low congestion times
• More use of uncongested roads

CADRE Travel time predictions at different times Better route selection Dynamic vehicle routing

CADRE

NAV08

Slide 6

Overview 


Mobile
 phone
 data
 GPS
 vehicle
 data
 Roadside
 sensors


Routing
 engine



Routes
 Route
 requests
 Road
 network


Speed
 data
 Speed
 engine
 Speed
 model


Road
 network
 Speed
 reports
 Speed
 limits


CADRE

NAV08

Slide 7

Architecture 


Long Term Model Short Term Model Journey Data Road Network Data Routing Engine Speed Engine Specific Road Model Data Generic Road Model Data Snapping Engine Journey Data Routing Information Data Logger Routing Client Map Server

CADRE

NAV08

Slide 8

Journey
Data


Mobile
Phone


• r
Logger


Data
Ingest
 Reject
Bad
 Data
 Snap
to
Roads
 Reject
 Unsnappable
 Data
 Add
to
Data
 Store


CADRE

NAV08

Slide 9

Snapped
Data


Snapping Development (since improved – about 90% pass rate) Green OK, Blue failed, since improved, Gold other journeys.

CADRE

NAV08

Slide 10

Speed
Engine
Scales 


CADRE

NAV08

Slide 11

Long
Term
Speed
Engine


• Core long term model in place
• Provides speeds for each road segment varying

by time of day and day of week

• Long term model in process of improvement
• Short term model being developed in Matlab

CADRE

NAV08

Slide 12

Generic
Speed
Model


• For
roads
where
there
is
no
specific
model

• Spread
of
data
currently
being
reduced
by
better
modelling

• Model
training
also
being
enhanced
and
automated


A
road
dual
carriageway,
70mph
speed
limit,
Monday


CADRE

NAV08

Slide 13

Arc
Specific
Model


• A
model
is
created
for
a
specific
arc
once
there
is
enough
data
of
good


enough
quality


• The
model
is
based
on
the
generic
one
for
that
arc
and
then
recalculated


using
the
data
for
that
arc


CADRE

NAV08

Slide 14

Short
Term
Model


• Aim
is
to
detect
congestion
from
live
traffic
data,
and
then
create
a
short


term
predictive
model
based
on
that


• This
part
of
the
speed
model
is
still
in
the
initial
modelling
phase


LTM Speed Time
of
day Now STM Data

CADRE

NAV08

Slide 15

Routing
Engine


• Minimum time or minimum distance route
• Uses speed limit or CADRE speed model or

speed model capped by speed limit

• Optimised for time varying road speeds
• Heuristics, such as pruning, to aid performance
• Always finds the true optimal route

CADRE

NAV08

Slide 16

Routing
Engine


CADRE

NAV08

Slide 17

Hindhead
Traffic
Lights


• Journey time using speed engine is more

accurate than using speed limit data or via Michelin

• Routing shows that in this case it pays to stay
• n the congested main road for almost all of the

time, rather than to divert down narrow country lanes

CADRE

NAV08

Slide 18

Routing
Client 


CADRE

NAV08

Slide 19

Sample
Results
‐
Hindhead


Minimum Time – Speed Limit Minimum Distance

CADRE

NAV08

Slide 20

Sample
Results
‐
Hindhead


Minimum Time – Speed Engine – 12.30 Minimum Time – Speed Engine – 08.00

CADRE

NAV08

Slide 21

Results
Comparison 


Hindhead 12.30 Red distance, Blue time

Slide 22 CADRE NAV08

CADRE
 
•
 NAV08
Presentation


November
2008