UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

NATIONAL VEHICLE AND FUEL EMISSIONS LABORATORY

2000 TRAVERWOOD DRIVE

ANN ARBOR, MI  48105-2498

									     OFFICE OF

									AIR AND RADIATION

July 2016

MEMORANDUM

SUBJECT:  NREL Bi-Modal Vocational Vehicle Cluster Information

FROM:  L. Steele, EPA-OTAQ, Assessment and Standards Division

TO:  Greenhouse Gas Emissions Standards and Fuel Efficiency Standards
for Medium- and Heavy-Duty Engines and Vehicles - Phase 2 - Docket
EPA-HQ-OAR-2014-0827

This memorandum presents information produced as part of an interagency
agreement between EPA and the Department of Energy’s National
Renewable Energy Laboratory to characterize vocational vehicle drive
cycles.

Figure 1 and Table 1 present information that is included in the final
drive cycle report dated July 2016.  Table 2 presents interim
information that was shared with EPA during a December 2015 progress
update.

Figure   SEQ Figure \* ARABIC  1 :  Two clustering using k-medoids
algorithm with cluster centers marked in black

(See Figure 6 of final report)

Table   SEQ Table \* ARABIC  1 : Vocational Drive Cycles –
2-Clustering Centers (See Table 4 of final report)

 	Aerodynamic Speed Standard (ft/s)	Characteristic Acceleration
Standard (ft/s2)	Percent Mileage Below 55 mph	Percent Time at 0 mph	Mean
stops/ mile	Mean driving speed (mph)	Max driving speed (mph)	Driving
speed Std Dev (mph)

Left (Slow) Cluster	54.59	0.48	91.08	50.62	2.68	21.26	59.22	16.28

Right (Fast) Cluster	81.21	0.28	26.62	22.11	0.24	43.76	65.01	21.06



Table   SEQ Table \* ARABIC  2 :  Possible Two-Cluster Cycle Weightings

Cluster	Percent of mileage accumulated < 55 mph	Percentage of mileage
accumulated between 55 and 65 mph	Percentage of mileage accumulated > 65
mph	Percentage of Cycle Time at Zero Speed

FDNA 1	91.38	8.62	0.00	51.15

MOVES 1	86.56	13.31	0.13	51.94

MOVES 1 SUB	87.60	11.51	0.90	58.07

FDNA 2	27.86	64.64	7.50	21.74

MOVES 2	30.28	58.46	11.26	23.11

MOVES 2 SUB	45.31	45.64	9.05	33.55



In Table 2, the cluster identifier FDNA 1 denotes the statistics
represent the full Fleet DNA database of vocational vehicles for cluster
1 (the slow left cluster characterized in Table 1).  In Table 2, the
cluster identifier FDNA 2 denotes the statistics represent the full
Fleet DNA database of vocational vehicles for cluster 2 (the fast right
cluster characterized in Table 1). The cluster identifiers MOVES 1,
MOVES 1 SUB, MOVES 2, and MOVES 2 SUB denote the statistics represent a
sub-sample of the fleet DNA database, as described in Chapter 2.3 of the
final drive cycle report.

 National Renewable Energy Laboratory July 2016, “The Development of
Vocational Vehicle Drive Cycles and Segmentation,” NREL/TP-5400-65921

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