|
|
|
|
|
Nomadic devices
|
|
Nomadic devices are probably not suitable for ISIG since
the volume of traffic and the latency in cellular communications could be
limiting factors
|
|
Since DSRC is being used for safety applications, ISIG can
listen for BSM messages at an intersection with little additional effort.
|
|
Level of Market
Penetration
|
|
EVP and TSP are low hanging fruit as these fleets are
generally owned and operated by public agencies.
|
|
FSP is similar, but the fleet is diversely owned and
operated.
|
|
Early results indicate that about 25% market penetration is
needed for ISIG and PERF MEAS
|
|
PERF MEAS could be effective with lower market penetration
if longer time frames are considered (to get several observations)
|
|
Possible Effects of
Communication Errors and Latency
|
|
The use cases for priority requests (EVP, TSP, and FSP)
include acknowledgement confirmation, so random communication loss should not
have an impact unless complete loss occurs.
|
|
A few seconds of latency in the priority use cases will
only result in slight impact to performance.
|
|
Latency in ISIG can impact the Dilemma Zone protection and
signal performance.
|
|
The marginal benefit
with data from existing sensors
|
|
ISIG benefits from existing detection when the market
penetration is low (or when the traffic volume is low and market penetration
is medium)
|
|
Vehicles need to be observed (detected) to alert the
controller that a vehicle needs to be served.
|
|
Current EV and TSP sensors provide some level of data that
can be used in priority applications, but the standards (SAE) support system
level interoperability and the algorithms (EVP, TSP, and FSP) are more
advanced than existing algorithms
|
|
The modal benefits
of connected vehicle data are critical
|
|
Knowing that a vehicle is transit, truck, or EV can
significantly impact the ability to provide safe priority
|
|
Signal control can benefit significantly using connected
vehicle data to measure queue length, saturation flow rates, startup lost
time, etc. These measures are not available without CV data
|
|
Pedestrians (and bicycles) will be significant
beneficiaries (using cellular)
|
|
Performance observation is not possible without CV data
[This could be one of the biggest benefits and doesnt depend on only MMITSS
it should be part of every DMA]
|
|
Potential Deployment
Impacts
|
|
Near Term Impacts
|
|
Significant benefits for priority control: EVP, TSP and FSP
in an integrated, multiple vehicle environment
|
|
Mobility for disable pedestrians using the PED SIG
application
|
|
Mid Term Impacts
|
|
Performance Observation by Mode (near term for EVP, TSP,
and FSP)
|
|
Improved Signal Control (ISIG) as market penetration
increases
|
|
Long Term Impacts
|
|
Reduced dependence on complex infrastructure based
detection systems (only 1 RSE required)
|
|
Ability to adjust traffic control policy (priority) based
on mode (and movement)
|