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United States-Mexico Land Ports of Entry Emissions and Border Wait-Time White Paper and Analysis Template

4.0 Case Studies

This section provides specific examples of how the information presented in Section 3.0 can be applied to evaluate emissions at a specific border crossing, as well as ways to evaluate alternative control strategies or scenarios at the border crossing.

4.1 Characteristics of Border Crossing Used in Case Studies

Ysleta-Zaragoza (Zaragoza) is located in eastern El Paso. It connects to I-10 via State Highway 375 (North Americas Avenue). Southbound passenger vehicles are tolled at $2.50, commercial vehicles at $3.50 per axle, and pedestrians at $0.50. Northbound tolls are 23 pesos for passenger vehicles, 137 pesos for commercial vehicles (5 axles), and 5 pesos for pedestrians. A northbound dedicated commuter lane (DCL) booth is available at Zaragoza. Drivers pay 24 pesos per DCL crossing in addition to CBP's 5-year SENTRI enrollment fee. The bridge currently is open 24 hours per day for private vehicles and from 6 a.m. to midnight (Monday-Friday) for commercial vehicles.

Two case studies are presented:

• Case Study 1: Shift 1,000 privately owned vehicles into the SENTRI program to reduce the amount of VMT in creeping queues.
• Case Study 2: Combine U.S. and Mexican commercial vehicle inspections to reduce the number of vehicle starts and idle time.

To simplify the presentation the case studies focus on daily average conditions for summer in 2010. Two pollutants are considered, oxides of nitrogen (NO_x) and fine particulate matter (PM_2.5). Both strategies being analyzed consider northbound traffic only. In the following section, composite emission rates common to both case studies are developed. Subsequent sections then apply those rates to estimate emission inventories for a no-action alternative and for each case study strategy.

4.2 Development of Composite Emission Rates

Composite emission rates for PM_2.5 are developed within this example, and corresponding calculations are available separately for NO_x. Subsequent portions of the case study then apply both sets of composite emission rates to quantify PM_2.5 and NO_x emissions. The starting point for developing composite emission factors are the MOVES emission rates estimated for the El Paso port of entry as part of this study (provided with the supplementary electronic data accompanying this report). Three weighted averages are applied:

• Time-of-day weighting factors (Table 3.4);
• Gasoline/diesel fractions (Table 3.5); and
• Vehicle class weighting factors (Table 3.6).

Weighted averages are applied in two steps to develop the composite emission factors. First, the time-of-day factors and gasoline/diesel fractions are applied; then the vehicle class weighting factors are applied to the results to produce composite PM_2.5 and NO_x emission rates for uncongested movements, creeping queues, stop-and-go queues, idle, and vehicle starts. The calculations are walked through separately for each process below.

Case-Specific Running Exhaust Composite Emission Factors

Time-of-day factors and gasoline/diesel fractions are applied to running exhaust emission rates in three tables:

• Table 4.1 Development of Case-Specific 2010 Daily Composite Uncongested Running Exhaust Emission Factors for PM_2.5;
• Table 4.2 Development of Case-Specific 2010 Daily Composite Creeping Queue Running Exhaust Emission Factors for PM_2.5; and
• Table 4.3 Development of Case-Specific 2010 Daily Composite Stop-and-Go Queue Running Exhaust Emission Factors for PM_2.5.

Only composite PM_2.5 emission rates are provided here. NO_x emission rates were generated via a similar process; tables are available separately).

There are five sections in each of these tables. The first four sections correspond to the four periods of the day (i.e., 6-9 a.m., 9 a.m.-4 p.m., 4-7 p.m., and 7 p.m.-6 a.m.). Time-of-day weighting factors from Table 3.4 are listed at the top of each section. Each of the four sections lists unadjusted emission rates separately for gasoline powered vehicles and diesel powered vehicles; the weighting factors from Table 3.5 are listed in the right most column. The last section of the table provides composite emission rates for each vehicle class. These represent typical daily emissions in units of grams per mile reflecting the application of the time-of-day weights and the gasoline/diesel weights.

Vehicle class weights are then applied (Table 3.6) to produce the final composite emission rates for privately owned vehicles (POV), buses, and commercial vehicles (COM). The resulting composite rates are combined as Table 4.4. Note that Table 4.4 incorporates both the PM_2.5 emission rates developed here, and the NO_x emissions rates developed separately.

Note: Composite rates are the product of emission rate, time-of-day fraction, and gas/diesel fraction summed by vehicle type.

Note: Composite rates are the product of emission rate, time-of-day fraction, and gas/diesel fraction summed by vehicle type.

Note: Composite rates are the product of emission rate, time-of-day fraction, and gas/diesel fraction summed by vehicle type.

Table 4.4 Case-Specific Running Exhaust Emission Rates Composited Across Vehicle Classes
(g/mile)

	NB FAST Trucks	NB Unladen Trucks	NB Laden Trucks	SB Trucks (All)	NB Autos	NB SENTRI Autos	SB Autos (All)
Composite 2010 Daily Uncongested Movement Running Exhaust Emission Factors for PM2.5
POV	N/A	N/A	N/A	N/A	0.010	0.014	0.010
COM	0.692	0.746	0.668	0.741	N/A	N/A	N/A
BUS	N/A	N/A	N/A	N/A	0.880	N/A	0.880
Composite 2010 Daily Uncongested Movement Running Exhaust Emission Factors for NOx
POV	N/A	N/A	N/A	N/A	0.31	0.47	0.27
COM	9.48	10.09	9.05	10.04	N/A	N/A	N/A
BUS	N/A	N/A	N/A	N/A	8.61	N/A	8.61
Composite 2010 Daily Creeping Queue Running Exhaust Emission Factors for PM2.5
POV	N/A	N/A	N/A	N/A	0.054	0.056	0.054
COM	1.416	1.400	1.425	1.404	N/A	N/A	N/A
BUS	N/A	N/A	N/A	N/A	2.642	N/A	2.642
Composite 2010 Daily Creeping Queue Running Exhaust Emission Factors for NOx
POV	N/A	N/A	N/A	N/A	1.08	1.19	1.15
COM	19.27	19.28	19.27	18.85	N/A	N/A	N/A
BUS	N/A	N/A	N/A	N/A	26.86	N/A	26.86
Composite 2010 Daily Stop-and-Go Queue Running Exhaust Emission Factors for PM2.5
POV	N/A	N/A	N/A	N/A	0.099	0.100	0.100
COM	1.379	1.326	1.386	1.368	N/A	N/A	N/A
BUS	N/A	N/A	N/A	N/A	2.658	N/A	2.658
Composite 2010 Daily Stop-and-Go Queue Running Exhaust Emission Factors for NOx
POV	N/A	N/A	N/A	N/A	1.99	2.22	2.27
COM	17.89	17.65	17.69	17.95	N/A	N/A	N/A
BUS	N/A	N/A	N/A	N/A	26.86	N/A	26.86

Case-Specific Idle Exhaust Composite Emission Factors

Time-of-day factors and gasoline/diesel fractions are applied to idle exhaust emission rates in Table 4.5. The table has a similar format to those above, with five sections corresponding to the four periods of the day (i.e., 6-9 a.m., 9 a.m.-4 p.m., 4-7 p.m., and 7 p.m.-6 a.m.) and the daily composite rate in the fifth section. However, this table lists the time-of-day weighting factors in the right hand column to make better use of available space and the PM_2.5 and NO_x emission rates are both presented is this one table.

Vehicle class weights are then applied (Table 3.6) to produce the final composite emission rates for privately owned vehicles (POV), buses, and commercial vehicles (COM). The resulting composite rates are combined as Table 4.6.

Note: Fraction of daily activity for trucks is based on northbound laden truck activity.

Case Specific Vehicle Start/Re-Start Exhaust Composite Emission Factors

Time-of-day factors and gasoline/diesel fractions are applied to idle exhaust emission rates via the following table:

• Table 4.7 Development of Case-Specific 2010 Daily Composite Vehicle Start Emission Factors for PM_2.5.

Only composite PM_2.5 emission rates are provided here. NO_x emission rates were generated via a similar process; the table is available separately.

The table has a similar format to those above, with five sections corresponding to the four periods of the day (i.e., 6-9 a.m., 9 a.m.-4 p.m., 4-7 p.m., and 7 p.m.-6 a.m.) and the daily composite rate in the fifth section. Each of the four sections that correspond to the period of the day list unadjusted emission rates separately for gasoline powered vehicles and diesel powered vehicles. The gasoline/diesel weighting factors from Table 3.5 and time-of-day weighting factors from Table 3.4 are listed on the right. The last section of the table provides composite emission rates for each vehicle class.

Vehicle class weighting factors are then applied (Table 3.6) to produce the final composite emission rates for privately-owned vehicles (POV), buses, and commercial vehicles (COM). The resulting composite rates are combined as Table 4.8.

Table 4.7 Development of Case-Specific 2010 Daily Composite Vehicle Start Emission Factors for PM_2.5

	2010 PM2.5 Start Emission Factor by Pre-Start Soak Time (g/start)								Gas or Diesel Fraction	Fraction of Daily Activity Occurring During This Period
Pre-Start Soak Time (minutes)	<6	6 to 30	30 to 60	60 to 90	90 to 120	120 to 360	360 to 720	> 720
Summer AM Peak (6 a.m.-9 a.m.)
Gasoline
Passenger Car	0.022	0.025	0.030	0.035	0.036	0.038	0.032	0.037	99.5%	11%
Passenger Truck	0.034	0.038	0.048	0.054	0.056	0.060	0.059	0.051	98.5%	11%
Light Commercial Truck	0.028	0.031	0.039	0.044	0.046	0.049	0.047	0.042	89.5%	3%
Intercity Bus	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	11%
Single Unit Short-Haul Truck	0.029	0.031	0.043	0.049	0.052	0.058	0.056	0.063	9.4%	3%
Combination Short-Haul Truck	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	3%
Diesel
Passenger Car	0.894	1.098	1.160	1.229	1.259	1.331	1.068	1.186	0.5%	11%
Passenger Truck	0.177	0.201	0.224	0.234	0.243	0.257	0.260	0.245	1.5%	11%
Light Commercial Truck	0.202	0.232	0.259	0.272	0.283	0.300	0.305	0.290	10.5%	3%
Intercity Bus	0.038	0.039	0.043	0.047	0.052	0.059	0.101	0.142	100.0%	11%
Single Unit Short-Haul Truck	0.034	0.035	0.039	0.044	0.050	0.056	0.085	0.148	90.6%	3%
Combination Short-Haul Truck	0.034	0.035	0.039	0.045	0.050	0.053	0.100	0.136	100.0%	3%
Summer Midday (9a.m.-4 p.m.)
Gasoline
Passenger Car	0.013	0.015	0.021	0.025	0.027	0.026	0.034	0.034	99.5%	38%
Passenger Truck	0.019	0.020	0.031	0.038	0.040	0.041	0.051	0.053	98.5%	38%
Light Commercial Truck	0.015	0.017	0.025	0.031	0.033	0.033	0.042	0.043	89.5%	42%
Intercity Bus	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	38%
Single Unit Short-Haul Truck	0.013	0.016	0.029	0.037	0.039	0.043	0.052	0.056	9.4%	42%
Combination Short-Haul Truck	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	42%
Diesel
Passenger Car	0.709	0.833	0.955	1.041	1.079	1.053	1.231	1.204	0.5%	38%
Passenger Truck	0.105	0.115	0.146	0.162	0.172	0.175	0.226	0.261	1.5%	38%
Light Commercial Truck	0.116	0.129	0.166	0.184	0.196	0.201	0.262	0.305	10.5%	42%
Intercity Bus	0.011	0.012	0.015	0.021	0.026	0.026	0.077	0.143	100.0%	38%
Single Unit Short-Haul Truck	0.002	0.002	0.007	0.013	0.018	0.024	0.068	0.134	90.6%	42%
Combination Short-Haul Truck	0.015	0.016	0.020	0.025	0.032	0.036	0.081	0.134	100.0%	42%
Summer PM Peak (4 p.m.-7 p.m.)
Gasoline
Passenger Car	0.014	0.017	0.022	0.025	0.028	0.028	0.033	0.037	99.5%	16%
Passenger Truck	0.023	0.027	0.036	0.041	0.045	0.045	0.051	0.057	98.5%	16%
Light Commercial Truck	0.019	0.022	0.029	0.034	0.036	0.036	0.042	0.046	89.5%	26%
Intercity Bus	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	16%
Single Unit Short-Haul Truck	0.018	0.013	0.033	0.040	0.039	0.046	0.054	0.058	9.4%	26%
Combination Short-Haul Truck	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	26%
Diesel
Passenger Car	0.746	0.875	0.987	1.025	1.095	1.085	1.186	1.269	0.5%	16%
Passenger Truck	0.118	0.141	0.162	0.172	0.186	0.187	0.220	0.272	1.5%	16%
Light Commercial Truck	0.131	0.160	0.184	0.197	0.214	0.216	0.257	0.319	10.5%	26%
Intercity Bus	0.046	0.047	0.052	0.058	0.061	0.066	0.104	0.145	100.0%	16%
Single Unit Short-Haul Truck	0.003	0.003	0.008	0.014	0.018	0.025	0.069	0.134	90.6%	26%
Combination Short-Haul Truck	0.006	0.006	0.011	0.016	0.021	0.026	0.072	0.137	100.0%	26%
Summer Overnight (7 p.m.-6 a.m.)
Gasoline
Passenger Car	0.013	0.017	0.021	0.025	0.028	0.026	0.032	0.037	99.5%	35%
Passenger Truck	0.013	0.019	0.028	0.035	0.036	0.038	0.046	0.051	98.5%	35%
Light Commercial Truck	0.010	0.015	0.023	0.028	0.029	0.031	0.037	0.042	89.5%	29%
Intercity Bus	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	35%
Single Unit Short-Haul Truck	0.006	0.010	0.020	0.027	0.029	0.034	0.042	0.046	9.4%	29%
Combination Short-Haul Truck	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	0.0%	29%
Diesel Summer
Passenger Car	0.697	0.905	0.931	1.020	1.102	1.021	1.178	1.271	0.5%	35%
Passenger Truck	0.073	0.115	0.137	0.150	0.153	0.161	0.203	0.254	1.5%	35%
Light Commercial Truck	0.078	0.127	0.153	0.168	0.172	0.183	0.234	0.296	10.5%	29%
Intercity Bus	0.075	0.076	0.080	0.086	0.092	0.098	0.133	0.141	100.0%	35%
Single Unit Short-Haul Truck	N/A	0.001	0.006	0.011	0.017	0.022	0.066	0.132	90.6%	29%
Combination Short-Haul Truck	0.066	0.067	0.071	0.077	0.082	0.088	0.066	0.198	100.0%	29%
Summer Daily Composite
Passenger Car	0.018	0.021	0.027	0.031	0.034	0.033	0.039	0.042	Combined	100%
Passenger Truck	0.020	0.024	0.034	0.041	0.043	0.045	0.053	0.056	Combined	100%
Light Commercial Truck	0.025	0.031	0.041	0.047	0.050	0.052	0.063	0.071	Combined	100%
Intercity Bus	0.042	0.043	0.047	0.053	0.058	0.061	0.104	0.143	Combined	100%
Single Unit Short-Haul Truck	0.003	0.004	0.010	0.015	0.020	0.026	0.066	0.126	Combined	100%
Combination Short-Haul Truck	0.028	0.029	0.033	0.038	0.044	0.049	0.075	0.153	Combined	100%

Note: Fraction of daily activity for trucks is based on northbound laden truck activity.

Table 4.8 Case-Specific Stat Exhaust Emission Rates Composited Across Vehicle Classes
(g/start)

	<6	6 to 30	30 to 60	60 to 90	90 to 120	120 to 360	360 to 720
Composite 2010 daily vehicle start emission factors for PM2.5
POV	0.02	0.02	0.03	0.03	0.04	0.04	0.04
COM	0.02	0.02	0.03	0.03	0.04	0.04	0.07
BUS	0.04	0.04	0.05	0.05	0.06	0.06	0.10
Composite 2010 daily vehicle start emission factors for NOx
POV	1.07	1.46	2.05	2.30	2.35	2.15	2.16
COM	0.36	0.48	0.78	0.86	0.85	0.82	0.81
BUS	N/A	N/A	N/A	N/A	N/A	N/A	N/A

4.3 Case Study No-Action Alternative

The northbound passenger vehicle process at the Ysleta-Zaragoza bridge is shown in Figure 4.1 and Figure 4.2. Northbound passenger vehicles traveling into the United States from Mexico must first pay a toll on the Mexican side of the border (PN 1). Following toll collection, vehicles cross the bridge into the United States. Here, passenger vehicles are divided into one of three lane types: Standard, SENTRI, or Ready Lane. Vehicles then enter CBP primary inspection booths (PN 2). Following primary inspection processing, vehicles are either directed to exit the POE or to enter secondary inspection (PN 3). Secondary inspections include more detailed reviews of both drivers and the vehicle. Following secondary inspections at both crossing, vehicles are directed to exit the facility and are free to travel to their destination in the United States.

The northbound process for commercial vehicle movements at the Yselta-Zaragoza border crossings is shown in the Figure 4.3 aerial and Figure 4.4 flow chart. As commercial vehicles travel northbound approaching the border on the Mexican side at the Ysleta-Zaragoza crossing they must first pay a toll (CN 1). The next step is processing by Mexican customs (CN 2). Prior to processing by Mexican customs, U.S. and Mexican brokers prepare and file the Mexican Pedimento and the U.S. Inward Cargo Manifest. Transfer of these documents to the commercial vehicle operators usually occurs at a broker office in the immediate vicinity of the border crossing, on a roadside prior to the Mexican export compound, or while the truck is waiting in a queue to cross the border.

The processing by Mexican customs (CN 2) includes the verification of all documentation. Once this is complete, the commercial vehicle either is routed to the inspection facility (CN 3) or directed to bypass this and drive through the inspection area and to the exit (CN 4). Less than 10 percent of vehicles are randomly selected and are sent from the booths (CN 2) to export inspections (CN 3). The main purpose of these inspections is to ensure that all applicable export duties and taxes are paid. Export inspections may involve the partial or complete unloading of a trailer and can take anywhere from 30 minutes to several hours. Commercial vehicles arrive at the exit of Mexican Customs either directly from the entry booths or following the inspection (CN 4).

Figure 4.1 Northbound Passenger Processes Aerial

Source: Cambridge Systematics, Inc., © 2012 Google, and INEGI (INSTITUTO NACIONAL DE ESTADÍSTICA Y GEOGRAFÍA).

Figure 4.2 Northbound Passenger Processes Flowchart

Source: Cambridge Systematics, Inc.

Figure 4.3 Northbound Commercial Processes Aerial

Source: Cambridge Systematics, Inc., © 2012 Google, and INEGI (INSTITUTO NACIONAL DE ESTADÍSTICA Y GEOGRAFÍA).

Figure 4.4 Northbound Commercial Processes Flowchart

Source: Cambridge Systematics, Inc.

Upon exiting the Mexican Customs processes, vehicles cross the bridge and enter the United States facilities. U.S. Customs and Border Protection (CBP) primary inspection occurs at booths for designated FAST lanes, empties, or standard trucks (CN 5). FAST lanes are the two most western lanes at Ysleta-Zaragoza, with the lane adjacent to the FAST lanes primarily for empties. There is an x-ray machine right after the booth that checks the trailers while the driver drives through, getting activated by the space between the car and trailer. From the booths, the trucks are either sent to the exit (CN 7), or get directed to one of many secondary inspections (CN 6). Secondary inspections include Pylon (for FAST vehicles), VACIS, Gantry, or Eagle inspections. The VACIS inspection and Eagle inspection operate similarly. Trucks line up in a queue, drivers exit the vehicle, and a mobile x-ray unit drives along the length of the vehicles, scanning them. The Gantry is a building that trucks drive into, the driver exits, and the truck is scanned. If something is detected or the CBP officer wants to take a closer look, they are sent to the dock for further inspection. Following secondary inspection, vehicles are directed to the U.S. exit inspection (CN 7), where documentation is verified to ensure the vehicle went through all the necessary processes before being released. Additionally, U.S. DOT/Federal Motor Carrier Safety Administration (FMCSA) conduct inspections on certain vehicles following primary inspections and prior to a vehicle exiting.

Upon exiting the facility (CN 7), vehicles head to the TxDOT Border Safety Inspection Facility (BSIF) (CN 8). At the BSIF, the Texas Department of Public Safety (DPS) inspects trucks crossing into the United States using various procedures, usually starting with visual safety inspection and then proceeding to a detailed truck safety inspection if violations are found. The BSIFs incorporate ITS technologies to minimize delay at these locations, including dynamic message signs, static and weigh-in-motion scales, dimensioning in motion, and flow managers.

Northbound 2010 Activity Levels

Table 4.9 provides a summary of aggregate volume and delay data for the Ysleta-Zaragoza port of entry. The example queue length calculation results for the northbound direction in 2011 for both border crossings. Additional information was taken from Google Earth as follows:

• The approach to the border was assumed to start three miles from the U.S. Primary inspection booth for both privately owned vehicles and commercial traffic. The distance that vehicles travel in uncongested traffic was then estimated by subtracting the creeping queue and stop-and-go queue lengths from the three-mile approach distance.
• The creeping queue length within the cargo inspection area is estimated to be 0.6 miles long based on aerials.
• Creeping distance from FMCSA to Texas DPS is estimated at 0.25 miles, followed by a further 0.5 miles of uncongested travel to exit the facility.

Table 4.9 Northbound Queue and Delay Data Used for 2010

	Ysleta-Zaragoza
	POV	SENTRI	Trucks	FAST
Daily Traffic Volumes (Average during hours of operation.)	6,760	836	1,022 (681 Laden,341 Unladen)	350
Length of Booth Approach Lanes	275	275	275	275
Number of Bridge Lanes	2	1	2	2
Average Daily
Open Inspection Booths	7	2	4	1
Estimated Vehicles in Queue	200	N/A	52	20
Estimated delay			25 minute
Calculated Queue Length (feet) (Assume average POV length + spacing = 25 feet, average truck length + spacing = 65 feet.)	1,813	N/A	1,415	788
Observed Queue Length (feet)	2,000

Source: Supporting data collected from Customs and Border Protection (CBP), City of El Paso toll bridges, and traffic counts that were used to develop the Cambridge Systematics (2011) El Paso Regional Ports of Entry Operations Plan for the Texas Department of Transportation.

Calculations

A calculation summary is presented in Table 4.10, below. Inputs to the calculations include:

• Activity levels identified through the flowcharts in Figure 4.2 (POV port of entry) and Figure 4.4 (commercial port of entry);
• Volume and queuing estimates from Table 4.9;
• Running exhaust composite emission factors from Table 4.4;
• Idle exhaust composite emission factors from Table 4.6; and
• Vehicle start composite emission factors from Table 4.8.

Table 4.10 No-Action Alternative Activity and Emissions Tabulation

Process	Activity Description	Quantity	Units	Volume	NOx Rate	PM2.5 Rate	Units	NOx Lbs./Day	PM2.5 Lbs./Day
Northbound Private Vehicle Port of Entry (Mexican Jurisdiction)
Toll Collection	Stop-and-Go Queue	0.05	miles	7,025	1.99	0.099	g/mile	1.54	0.08
	Idle	1	minute	7,025	5.65	0.140	g/hour	1.46	0.04
Northbound Private Vehicle Port of Entry (U.S. Jurisdiction)
U.S. Primary, Buses (No transit buses utilize Ysleta-Zaragoza)	Uncongested	2.95	miles	N/A	8.61	0.880	g/mile	N/A	N/A
	Creeping Queue	0	miles	N/A	26.86	2.642	g/mile	N/A	N/A
	Stop-and-Go Queue	0.05	miles	N/A	26.86	2.658	g/mile	N/A	N/A
	Idle	5	minutes	N/A	54.46	6.680	g/hour	N/A	N/A
U.S. Primary, SENTRI	Uncongested	2.95	miles	275	0.47	0.014	g/mile	0.84	0.03
	Creeping Queue	0	miles	275	1.19	0.056	g/mile	-	-
	Stop-and-Go Queue	0.05	miles	275	2.22	0.100	g/mile	0.07	0.00
	Idle	1	minute	275	5.65	0.140	g/hour	0.06	0.00
U.S. Primary, General	Uncongested	2.25	miles	6,750	0.31	0.010	g/mile	10.38	0.33
	Creeping Queue	0.7	miles	6,750	1.08	0.054	g/mile	11.25	0.56
	Stop-and-Go Queue	0.05	miles	6,750	1.99	0.099	g/mile	1.48	0.07
	Idle	1	minute	6,750	5.65	0.140	g/hour	1.40	0.03
U.S. Secondary (Assumed to be 5% of general volume.)	Creeping Queue	0.05	miles	338	1.08	0.054	g/mile	0.04	0.00
	Restart (6-30 minute soak)	N/A		338	1.46	0.020	g/start	1.09	0.01
Subtotal (Northbound Private Vehicle Port of Entry)								29.60	1.16
Northbound Commercial Vehicle Port of Entry (Mexican Jurisdiction)
Toll Collection	Stop-and-Go Queue (FAST)	0.05	miles	350	17.89	1.379	g/mile	0.69	0.05
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.65	1.326	g/mile	0.66	0.05
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Export Customs Entrance	Stop-and-Go Queue (FAST)	0.05	miles	350	17.89	1.379	g/mile	0.69	0.05
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.65	1.326	g/mile	0.66	0.05
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Export Cargo Inspection	Creeping Queue (FAST)	0.05	miles	350	19.27	1.416	g/mile	0.74	0.05
	Creeping Queue (Unladen)	0.05	miles	341	19.28	1.400	g/mile	0.72	0.05
	Creeping Queue (Laden)	0.05	miles	681	19.27	1.425	g/mile	1.45	0.11
	Restart (30-60 minute soak)	N/A		1,372	0.78	0.030	g/start	2.36	0.09
Export Customs Exit	Stop-and-Go Queue (FAST)	0.05	miles	350	17.89	1.379	g/mile	0.69	0.05
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.65	1.326	g/mile	0.66	0.05
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Northbound Commercial Vehicle Port of Entry (U.S. Jurisdiction)
U.S. Primary	Uncongested (FAST)	2.95	miles	350	9.480	0.69	g/mile	21.58	1.58
	Creeping Queue (FAST)	0	miles	350	19.270	1.42	g/mile	N/A	N/A
	Stop-and-Go Queue (FAST)	0.05	miles	350	17.890	1.38	g/mile	0.69	0.05
	Uncongested (Unladen)	2.7	miles	341	10.090	0.75	g/mile	20.48	1.51
	Creeping Queue (Unladen)	0.25	miles	341	19.280	1.40	g/mile	3.62	0.26
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.650	1.33	g/mile	0.66	0.05
	Uncongested (Laden)	2.7	miles	681	9.050	0.67	g/mile	36.69	2.71
	Creeping Queue (Laden)	0.25	miles	681	19.270	1.425	g/mile	7.23	0.53
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
U.S. Secondary	Creeping Queue (Laden)	0.6	miles	681	19.280	1.40	g/mile	17.37	1.26
	Restart (6-30 minute soak)	N/A		681	0.48	0.020	g/start	0.72	0.03
U.S. Customs Exit	Stop-and-Go Queue (FAST)	0.05	miles	1,372	17.89	1.379	g/mile	2.71	0.21
	Stop-and-Go Queue (Unladen)	0.05	miles	1,372	17.65	1.326	g/mile	2.67	0.20
	Stop-and-Go Queue (Laden)	0.05	miles	1,372	17.69	1.386	g/mile	2.68	0.21
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Northbound Commercial Vehicle Port of Entry (State of Texas Jurisdiction)
Texas DPS Inspection	Uncongested (FAST)	0.5	miles	350	9.480	0.69	g/mile	3.66	0.27
	Creeping Queue (FAST)	0.25	miles	350	19.270	1.42	g/mile	3.72	0.27
	Stop-and-Go Queue (FAST)	0.05	miles	350	17.890	1.38	g/mile	0.69	0.05
	Uncongested (Unladen)	0.5	miles	341	10.090	0.75	g/mile	3.79	0.28
	Creeping Queue (Unladen)	0.25	miles	341	19.280	1.40	g/mile	3.62	0.26
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.650	1.33	g/mile	0.66	0.05
	Uncongested (Laden)	0.5	miles	681	9.050	0.67	g/mile	6.79	0.50
	Creeping Queue (Laden)	0.25	miles	681	19.270	1.425	g/mile	7.23	0.53
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Subtotal (Northbound Commercial Vehicle Port of Entry)								186.45	13.82
Northbound Port of Entry Total								216.06	14.98

As a point of reference, the emissions also can be estimated for the same volume of traffic and assuming no border crossing delay by assuming three miles of uncongested VMT (Table 4.11). The resulting estimate assumes no toll collection or inspections of any type occur, and establishes an estimate of the floor below which no operational strategies or infrastructure investment could reduce emissions.

Table 4.11 Hypothetical Emissions Without Any Delay

Activity Description	Quantity	Units	Volume	NOx Rate	PM2.5 Rate	Units	NOx Lbs./Day	PM2.5 Lbs./Day
POV (SENTRI)	3	miles	275	0.47	0.140	g/mile	0.85	0.25
POV (General)	3	miles	6,752	0.31	0.010	g/mile	13.84	0.45
Commercial (FAST)	3	miles	350	9.48	0.69	g/mile	21.94	1.60
Commercial (Unladen)	3	miles	341	10.09	0.75	g/mile	22.76	1.68
Commercial (Laden)	3	miles	681	9.05	0.67	g/mile	40.76	3.01
Hypothetical Emissions Without Any Delay							100.16	6.99

4.4 Case Study 1 Calculation

This strategy shifts 1,000 privately owned vehicles into the SENTRI program to reduce the amount of VMT in creeping queues. Because new border crossing capacity is constructed, it is assumed that general purpose lanes will be converted to SENTRI lanes for a portion of the day, and daily average queue lengths do not change relative to the no-action alternative.

Calculations

A calculation summary is presented in Table 4.12 below. Inputs to the calculations include:

• Activity levels identified through the flowcharts in Figure 4.2 (POV port of entry) and Figure 4.4 (commercial port of entry);
• Volume and queuing estimates from Table 4.9;
• Running exhaust composite emission factors from Table 4.4;
• Idle exhaust composite emission factors from Table 4.6; and
• Vehicle start composite emission factors from Table 4.8.

The commercial vehicle portion of the calculation table is identical to the no-action scenario. The presentation of commercial vehicle results is simplified in this example to highlight the portions of the calculations impacted by the case study strategy.

Table 4.12 POV Strategy Activity and Emissions Tabulation

Process	Activity Description	Quantity	Units	Volume	NOx Rate	PM2.5 Rate	Units	NOx Lbs./Day	PM2.5 Lbs./Day
Northbound Private Vehicle Port of Entry (Mexican Jurisdiction)
Toll Collection	Stop-and-Go Queue	0.05	miles	7,025	1.99	0.099	g/mile	1.54	0.08
	Idle	1	minute	7,025	5.65	0.140	g/hour	1.46	0.04
Northbound Private Vehicle Port of Entry (U.S. Jurisdiction)
U.S. Primary, Buses (No transit buses utilize Ysleta-Zaragoza.)	Uncongested	2.95	miles	N/A	8.61	0.880	g/mile	N/A	N/A
	Creeping Queue	0	miles	N/A	26.86	2.642	g/mile	N/A	N/A
	Stop-and-Go Queue	0.05	miles	N/A	26.86	2.658	g/mile	N/A	N/A
	Idle	5	minutes	N/A	54.46	6.680	g/hour	N/A	N/A
U.S. Primary, SENTRI	Uncongested	2.95	miles	1,275	0.47	0.014	g/mile	3.90	0.12
	Creeping Queue	0	miles	1,275	1.19	0.056	g/mile	N/A	N/A
	Stop-and-Go Queue	0.05	miles	1,275	2.22	0.100	g/mile	0.31	0.01
	Idle	1	minute	1,275	5.65	0.140	g/hour	0.26	0.01
U.S. Primary, General	Uncongested	2.25	miles	5,750	0.31	0.010	g/mile	8.84	0.29
	Creeping Queue	0.7	miles	5,750	1.08	0.054	g/mile	9.58	0.48
	Stop-and-Go Queue	0.05	miles	5,750	1.99	0.099	g/mile	1.26	0.06
	Idle	1	minute	5,750	5.65	0.140	g/hour	1.19	0.03
U.S. Secondary (Assumed to be five percent of general volume.)	Creeping Queue	0.05	miles	338	1.08	0.054	g/mile	0.04	0.00
	Restart (6-30 minute soak)	N/A		338	1.46	0.020	g/start	1.09	0.01
Subtotal (Northbound Private Vehicle Port of Entry)								29.48	1.12
Subtotal (Northbound Commercial Vehicle Port of Entry from No-Action Alternative)								186.45	13.82
Northbound Port of Entry Total								215.93	14.94

4.5 Case Study 2 Calculations

This strategy would combine the Mexican and U.S. cargo inspection procedures at a single facility. Such a strategy is an extension of pilot programs starting in Fall 2012 where North American imports arriving at ports in Montreal and Prince Rupert, British Columbia would be cleared for entrance into the United States without the need for a second round of inspection at the border. A modified process flow chart is provided as Figure 4.5. After the toll collection at the entrance to the border crossing, trucks would proceed to a common cargo inspection area that would operate similarly to the existing U.S. cargo screening area.

Calculations

A calculation summary is presented in Table 4.13 below. Inputs to the calculations include:

• Activity levels identified through the flowcharts in Figure 4.2 (POV port of entry) and Figure 4.4 (commercial port of entry);
• Volume and queuing estimates from Table 4.9;
• Running exhaust composite emission factors from Table 4.4;
• Idle exhaust composite emission factors from Table 4.6; and
• Vehicle start composite emission factors from Table 4.8.

The privately owned (passenger) vehicle portion of the calculation table is identical to the no-action scenario. The presentation of passenger vehicle results is simplified in this example to highlight the portions of the calculations impacted by the case study strategy.

Figure 4.5 Northbound Commercial Processes Flowchart
Case Study 2

Source: Cambridge Systematics, Inc.

Table 4.13 Commercial Vehicle Strategy Activity and Emissions Tabulation

Process	Activity Description	Quantity	Units	Volume	NOx Rate	PM2.5 Rate	Units	NOx Lbs./Day	PM2.5 Lbs./Day
Subtotal (Northbound Private Vehicle Port of Entry from No-Action Alternative)								29.60	1.16
Northbound Commercial Vehicle Port of Entry (Mexican Jurisdiction)
Toll Collection	Stop-and-Go Queue (FAST)	0.05	miles	350	17.89	1.379	g/mile	0.69	0.05
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.65	1.326	g/mile	0.66	0.05
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Northbound Commercial Vehicle Port of Entry (Combined Mexican and U.S. Jurisdiction)
Combined Primary	Uncongested (FAST)	2.95	miles	350	9.480	0.69	g/mile	21.58	1.58
	Creeping Queue (FAST)	0	miles	350	19.270	1.42	g/mile	N/A	N/A
	Stop-and-Go Queue (FAST)	0.05	miles	350	17.890	1.38	g/mile	0.69	0.05
	Uncongested (Unladen)	2.7	miles	341	10.090	0.75	g/mile	20.48	1.51
	Creeping Queue (Unladen)	0.25	miles	341	19.280	1.40	g/mile	3.62	0.26
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.650	1.33	g/mile	0.66	0.05
	Uncongested (Laden)	2.7	miles	681	9.050	0.67	g/mile	36.69	2.71
	Creeping Queue (Laden)	0.25	miles	681	19.270	1.425	g/mile	7.23	0.53
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Combined Secondary	Creeping Queue (Laden)	0.6	miles	681	19.280	1.40	g/mile	17.37	1.26
	Restart (6-30 minute soak)	N/A		681	0.48	0.020	g/start	0.72	0.03
Combined Customs Exit	Stop-and-Go Queue (FAST)	0.05	miles	1,372	17.89	1.379	g/mile	2.71	0.21
	Stop-and-Go Queue (Unladen)	0.05	miles	1,372	17.65	1.326	g/mile	2.67	0.20
	Stop-and-Go Queue (Laden)	0.05	miles	1,372	17.69	1.386	g/mile	2.68	0.21
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Northbound Commercial Vehicle Port of Entry (State of Texas Jurisdiction)
Texas DPS Inspection	Uncongested (FAST)	0.5	miles	350	9.480	0.69	g/mile	3.66	0.27
	Creeping Queue (FAST)	0.25	miles	350	19.270	1.42	g/mile	3.72	0.27
	Stop-and-Go Queue (FAST)	0.05	miles	350	17.890	1.38	g/mile	0.69	0.05
	Uncongested (Unladen)	0.5	miles	341	10.090	0.75	g/mile	3.79	0.28
	Creeping Queue (Unladen)	0.25	miles	341	19.280	1.40	g/mile	3.62	0.26
	Stop-and-Go Queue (Unladen)	0.05	miles	341	17.650	1.33	g/mile	0.66	0.05
	Uncongested (Laden)	0.5	miles	681	9.050	0.67	g/mile	6.79	0.50
	Creeping Queue (Laden)	0.25	miles	681	19.270	1.425	g/mile	7.23	0.53
	Stop-and-Go Queue (Laden)	0.05	miles	681	17.69	1.386	g/mile	1.33	0.10
	Idle	1	minute	1,372	76.74	6.130	g/hour	3.87	0.31
Subtotal (Northbound Commercial Vehicle Port of Entry)								168.08	12.48
Northbound Port of Entry Total								197.68	13.65