![](media/image1.png)

Final Site Report

######## **Evaluation of Travel**

**[Time Methods to Support]{.smallcaps}**

**[Mobility Performance]{.smallcaps}**

**[Monitoring]{.smallcaps}**

**[Blue Water Bridge]{.smallcaps}**

To

Office of Freight Mgt. and Operations

Federal Highway Administration

U.S. Department of Transportation

Washington, DC 20590

 April 2002

# Border Crossing Freight Delay Data Collection and Analysis

## FY 2001 Data Collection -- Blue Water Bridge

####### Site Description

The Blue Water Bridge connects Port Huron, Michigan with Point Edward
and Sarnia, Ontario and crosses the Saint Clair River. The bridge is
near the intersection of I-94 and I-69 in the U.S., connecting with
Detroit and Flint, Michigan and Chicago, Illinois. In Canada, the bridge
connects with Highway 402, a major highway that connects to Highway 401
in London, Ontario, which extends from Detroit, Michigan through
Toronto, Ontario and into the Eastern Provinces. The bridge facilitates
the movement of many commodities between the U.S. and Canada, with the
automotive and agricultural industries the most notable. The bridge
operates 24 hours a day, seven days a week.

The Blue Water Bridge comprises two spans, each with three lanes. The
original bridge, built in 1938, was refurbished in 1999 and handles
westbound traffic into the U.S. The second span, opened in 1997, handles
outbound traffic into Canada. The bridge is open for both passenger and
commercial vehicle traffic 24 hours a day. The bridge is unique in that
it is not jointly owned by entities on both sides but, rather, the U.S.
side of the bridge is owned by the State of Michigan and operated by the
Michigan Department of Transportation and the Canadian side is owned and
operated by the Blue Water Bridge Authority. These two organizations
seem to cooperate quite well with each other but need to maintain
separate operations and maintenance staffs.

![](media/image2.png){width="4.791666666666667in"
height="3.5104166666666665in"}

**Figure 1. Area Map -- The Blue Water Bridge**

## Data collection activities at the Blue Water Bridge occurred during June 12-14, 2001 and August 14-16, 2001. Truck travel times across the bridge in both directions were recorded on Tuesday through Thursday each week, for approximately 12 hours each day. The times of the data collection were staggered somewhat to obtain a broader picture of activity at the bridge.

![](media/image3.png){width="6.5in" height="2.3895833333333334in"}

## Figure 2. Blue Water Bridge Plazas

Eastbound traffic (outbound to Canada) approaches the bridge either from
I-94 or from a local road. The Duty Free Store is located at the
intersection of the local road and the ramp to the bridge. All vehicles
exiting the Duty Free Store must proceed across the bridge to Canada.
Often, drivers must meet with their brokers prior to leaving the U.S.
and will park along the right shoulder before the toll booths and cross
the travel lanes to the brokerage building on the inbound side of the
U.S. plaza. The toll booth on the U.S. side has five booths, one of
which is reserved for autos with exact change or tokens. The other four
booths can process either autos or trucks. Once across the bridge, autos
are directed to the left and trucks veer off to the right to pass
through one of four primary Customs inspection booths. Trucks are either
released from primary or must continue on to secondary inspection, which
could include simply completing brokerage paperwork or physical
inspections of the cargo. Trucks requiring physical inspections enter an
area adjacent to the buildings on the left as they exit; whereas trucks
whose drivers must interact with their broker park in the areas to the
right and behind the primary inspection booths. When these trucks are
finally ready to depart, they must use the same roadway that trucks
released from primary must use to exit the Customs compound.

Westbound (inbound to the U.S.) traffic approaches the bridge from
Highway 402. During both data collection visits, there was construction
work on Highway 402 in both directions beginning several miles from the
bridge. Highway 402, which is a divided highway, was reduced to a single
lane in each direction for a stretch of many miles. A currency exchange
and public restrooms are conveniently located on the Canadian plaza and
trucks often stop along the right shoulder of the road and cross the
travel lanes to visit these facilities. There are typically two toll
booths open for all vehicles (primarily used by trucks), one for cars
and trailers, and two automated car booths. As the U.S. plaza requires
trucks to stay to the left and autos to stay to the right, the Canadian
Blue Water Bridge Authority restricts the flow of cars and trucks after
the toll booths to the leftmost lane. This forces trucks into their
desired position and allows cars to move to the right side of the bridge
safety and eliminates all conflicting crossing maneuvers. This
essentially creates a one-lane bottleneck on the three-lane bridge, but
this did not seem to impact vehicle movement significantly. There are
five booths to process commercial vehicles for U.S. Customs primary
inspection; however, typically only two to four are used at any one
time. Any truck not released from primary must enter the same secondary
inspection compound. There are areas to park for drivers who need to
visit their brokers as well as docks where physical secondary
inspections can be conducted. As with the Canadian side, trucks exiting
from secondary must pass through the area used by trucks exiting the
primary inspection booths. Anecdotal information indicated that the
limited physical space in the U.S. import compound occasionally fills up
and trucks requiring secondary inspection or clearance must be held at
the primary booths.

## 

## Data Collection Process

For this study, two data collection locations were used in each
direction. The "number 1" location was immediately before the toll
booths and the "number 2" location was immediately after the primary
inspection booths. For consistency among all border crossings visited as
part of the overall project, the data collection positions were
distinguished by the direction of travel that they were measuring
(outbound or inbound). Eastbound movement from the U.S. into Canada was
referred to as outbound. Conversely, inbound was used to refer to
westbound movement from Canada to the U.S. The Outbound 1 (OB-1)
position; therefore, is in the U.S. plaza, before the toll booths. The
Outbound 2 (OB-2) position was after the Canadian Customs booths.
Inbound positions (IB-1 and IB-2) were similarly positioned. All four
positions are identified in Figures 3 and 4 and shown in Figures 5
through 8.

Each data collector would use a handheld computer to record partial
license plate information of all commercial vehicles that passed their
location. The computer would also store the time that each license plate
was entered. The data from the two locations in each direction would be
combined, allowing the determination of the travel time for each vehicle
that was recorded at *both* locations.

![](media/image4.wmf)

## Figure 3. US Plaza Showing Data Collection Locations

![](media/image5.wmf)

## Figure 4. Canadian Plaza Showing Data Collection Locations

![](media/image6.wmf)

## 

## Figure 5. U.S. Toll Plaza Showing OB-1 Collection Location

## ![](media/image7.jpeg){width="6.5in" height="3.75in"}

## 

## Figure 6. U.S. Customs Primary Inspection Booths as Seen from IB-2 Collection Location

![](media/image8.jpeg){width="6.5in" height="1.975in"}

## 

## Figure 7. Canadian Toll Booths as Seen from IB-1 Collection Location

## ![](media/image9.jpeg){width="6.5in" height="4.875in"}

## Figure 8. OB-2 Collection Location in Canadian Customs Parking Area

For the first week of data collection, the on-site team included four
data collectors and one supervisor. It was later determined that an
additional supervisor was necessary to help provide additional security
for any collector in a #1 position who had to leave their initial
position and move away from the bridge plaza. These secondary locations
were often at or near rural highway intersections and were rather
isolated. The extra supervisor could also provide additional support to
take over data collection when a collector was given a break or lunch.

As previously mentioned, the hours during which data were collected were
varied during each week to ensure the greatest possible coverage of
conditions, including periods of low and high traffic volume. Table 1
shows the data collection hours for each day during the two site visits.
As each data collector actually worked about 12 hours, the supervisor
could collect data during their 30-minute meal break during the day,
resulting in approximately 12-½ hours of data collection.

## Table 1. Hours of Data Collection

  -------------------- ------------------------- -------------------------
  **Date**             **Start**                 **End**

  6/12/01              6:00 am                   6:30 pm

  6/13/01              9:00 am                   9:30 pm

  6/14/01              9:00 am                   9:30 pm

  8/14/01              6:00 am                   6:30 pm

  8/15/01              9:00 am                   9:30 pm

  8/16/01              9:00 am                   9:30 pm
  -------------------- ------------------------- -------------------------

While an extremely smooth process, it took considerable time to schedule
and arrange the initial site visits to coordinate the data collection
activities. Two separate meetings were held at the bridge. One meeting
was held at the Michigan Department of Transportation facilities at the
bridge with the Bridge Manager, the U.S. Customs Port Director, and the
U.S. Customs Chief Inspector. Another meeting was held at the Blue Water
Bridge Authority offices on the Canadian side. In attendance were the
Operations Manager, the Special Projects Manager, and the District
Director for Revenue Canada, Customs Border Services. It was determined
that U.S. Customs visitor passes would need to be obtained for the data
collectors from the shift supervisor when they arrived for the data
collection. The names and birth dates of the data collectors also needed
to be provided to U.S. Customs for the initial data collection visit.
This was not required for the second data collection visit, however. No
special passes were required for access to the Canadian Customs
facilities.

Initial contacts with Canadian Immigration while at the bridge indicated
that work permits were needed to conduct the data collection. However,
consultations with Canadian Consular officials in Buffalo in preparation
for data collection at the Peace Bridge indicated that that would not be
necessary. The Canadian Consul General in Detroit was contacted and his
staff determined that Annex 1603.A.1 of the North American Free Trade
Agreement would allow our staff to enter Canada as Business Visitors
without requiring work permits. All data collectors carried a copy of
the e-mail from the Vice Consul as authorization for our activities. In
addition, the Blue Water Bridge Authority staff communicated with the
Canadian Customs and Immigration supervisors to ensure that their staff
were aware of our visit.

Permission was obtained from the Michigan Department of Transportation
Bridge Manager for any data collection on I-94, should that be necessary
due to the formation of a queue. On the Canadian side, the Ontario
Provincial Police (OPP) is responsible for monitoring activity along
Highway 402, and the Blue Water Bridge Authority contacted the Sergeant
in charge of the area to ensure that he was aware of the study and to
obtain his permission to collect data along the highway. An additional
item that required attention during the first data collection visit was
contacting the foreman for the construction on Highway 402 to obtain his
permission to be within the construction site.

Table 2 contains a list of the individuals who were contacted and their
telephone and e-mail information. Future data collection for this
project should be able to be organized and authorized with much less
effort. However, any new project would require additional time to
explain the data collection objectives to the involved parties and gain
their approval.

## Table 2. Agency Contacts

+------------------+------------------+---------------+---------------+
| **Contact**      | **Agency**       | **Phone/Fax** | **E-mail**    |
+------------------+------------------+---------------+---------------+
| Bruce Campbell   | Michigan DOT     | 810-984-3131  | campbell5@    |
|                  |                  |               |               |
| Engineer/Bridge  | Blue Water       | 810-984-1810  | mdo           |
| Manager          | Bridge           | (fax)         | t.state.mi.us |
+------------------+------------------+---------------+---------------+
| Russell Day      | U.S. Customs     | 810-985-7125  | R             |
|                  |                  | ext.131       | ussell.h.day@ |
| Port Director    |                  |               |               |
|                  |                  | 810-985-3516  | cust          |
|                  |                  | (fax)         | oms.treas.gov |
+------------------+------------------+---------------+---------------+
| Robert Prause    | U.S. Customs     | 810-985-9541  |               |
|                  |                  | ext.117       |               |
| Chief Inspector  |                  |               |               |
+------------------+------------------+---------------+---------------+
| Joe Lopetrone    | Blue Water       | 519-337-8721  | jlopet        |
|                  | Bridge Authority |               | rone@bwba.org |
| Operations       |                  | 519-337-5877  |               |
| Manager          |                  | (fax)         |               |
+------------------+------------------+---------------+---------------+
| Ed Teft          | Blue Water       | 519-336-2720  |               |
|                  | Bridge Authority |               |               |
| Special Projects |                  | 519-336-7622  |               |
| & Bridge         |                  | (fax)         |               |
| Technology       |                  |               |               |
| Manager          |                  |               |               |
+------------------+------------------+---------------+---------------+
| W.L. (Bill)      | Revenue Canada   | 519-344-7351  | billelliott@  |
| Elliott          |                  |               |               |
|                  | Customs Border   | 519-336-5742  | cc            |
|                  | Services         | (fax)         | ra-adrc.gc.ca |
+------------------+------------------+---------------+---------------+
| John Tennant     | Consulate        | 313-446-7010  |               |
|                  | General of       | ext.3200      |               |
| Consul General   | Canada (Detroit) |               |               |
|                  |                  | 313-567-2164  |               |
|                  |                  | (fax)         |               |
+------------------+------------------+---------------+---------------+
| Bob Genereux     | Consulate        | 313-446-4732  | b.genereux@   |
|                  | General of       |               |               |
| Vice Consul      | Canada (Detroit) | 313-567-2125  | dfai          |
|                  |                  | (fax)         | t-maeci.gc.ca |
+------------------+------------------+---------------+---------------+
| Stan Korosek     | Ontario          | 519-336-8691  |               |
|                  | Provincial       |               |               |
| Sergeant         | Police           | 519-336-5011  |               |
|                  |                  | (fax)         |               |
|                  | Point Edward     |               |               |
|                  | Detachment       |               |               |
+------------------+------------------+---------------+---------------+
| Ken Doussept     | BOT Construction | 905-827-4167  | doussept@     |
|                  | Limited          |               |               |
| Project Manager  |                  | 905-827-0458  | botco         |
|                  | (Highway 402     | (fax)         | nstruction.ca |
|                  | Project)         |               |               |
|                  |                  | 519-330-9306  |               |
|                  |                  | (cell)        |               |
+------------------+------------------+---------------+---------------+

**Data Collection Details**

Both the Michigan Department of Transportation and the Blue Water Bridge
Authority provided border crossing statistical data. This data was
evaluated for an assessment of the variability in travel conditions at
the Blue Water Bridge. The goal of this analysis process was to obtain
statistically useful data with as few data collection days as possible.
In order to customize the data collection activities to the Blue Water
Bridge, the following steps were conducted:

-   Define significant "seasonal" variations,

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-   Define significantly different days of the week,

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-   Identify traffic streams that experience significantly different
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-   Estimate the number of days needed for the data collection survey.

As shown in Table 3, there is some variation in the commercial traffic
by month, which was most pronounced in 2000. Due to project constraints,
data collection needed to occur between late May and early September
2001. From Table 3, the two months with the greatest average volumes
during this data collection window were June and August.

**Table 3. Monthly Traffic Distribution of Commercial Vehicles**

  ---------------- ------------ ------------ ------------ ----------------
  **Month**        **1998**     **1999**     **2000**     **1998-2000
                                                          Average**

  January          105,313      111,071      122,961      113,115

  February         105,919      114,652      126,796      115,789

  March            117,456      132,440      144,109      131,335

  April            115,129      124,457      127,224      122,270

  May              114,844      126,057      143,081      127,994

  June             111,183      132,783      148,134      130,700

  July             91,459       105,845      111,411      102,905

  August           113,546      130,042      144,027      129,205

  September        119,176      133,327      132,295      128,266

  October          124,852      134,384      140,891      133,376

  November         121,358      133,504      132,846      129,236

  December         110,625      116,763      103,064      110,151

  **Total**        1,350,860    1,495,325    1,576,839    1,474,341
  ---------------- ------------ ------------ ------------ ----------------

Source: Texas Transportation Institute

Tables 4 and 5 show that there is a significant difference in commercial
traffic between weekdays and weekends and, further, there is a
significant difference between Monday and Friday and the three mid-week
days. Weekend traffic is 39 percent of typical weekday traffic and
Monday/Friday traffic is 85 percent of typical
Tuesday/Wednesday/Thursday traffic. In general, it was noted that
outbound traffic increased from Tuesday through Thursday and inbound
traffic decreased from Tuesday through Thursday. It was determined that
collecting three days of data, from Tuesday through Thursday, would
provide an adequate number of data samples to represent "typical"
conditions.

**Table 4. Sample Month -- Daily Traffic Distribution of Commercial**

**Vehicles for June 2000**

  -----------------------------------------------------------------------
  **Day**           **Day of Week**   **Outbound**      **Inbound**
  ----------------- ----------------- ----------------- -----------------
  1                 Thursday          3290              3230

  2                 Friday            3074              2638

  3                 Saturday          1327              1347

  4                 Sunday            879               1887

  5                 Monday            2616              3438

  6                 Tuesday           3014              3536

  7                 Wednesday         3158              3485

  8                 Thursday          3234              3231

  9                 Friday            2759              2491

  10                Saturday          1031              1177

  11                Sunday            788               1441

  12                Monday            2408              3109

  13                Tuesday           2996              3267

  14                Wednesday         3003              3365

  15                Thursday          3170              3148

  16                Friday            2785              2426

  17                Saturday          970               1111

  18                Sunday            805               1398

  19                Monday            2442              3177

  20                Tuesday           2878              3375

  21                Wednesday         2883              3321

  22                Thursday          3103              3104

  23                Friday            2670              2401

  24                Saturday          964               1113

  25                Sunday            824               1386

  26                Monday            2426              2999

  27                Tuesday           2856              3164

  28                Wednesday         2994              3225

  29                Thursday          2754              2886

  30                Friday            2278              1879

  **Total**                           70,379            77,755
  -----------------------------------------------------------------------

Source: Michigan Department of Transportation, Blue Water Bridge

**Table 5. Averages for Sample Month -- Daily Traffic Distribution of
Export Commercial Vehicles for June 2000**

  ----------- ---------- ---------- ---------- ---------- ---------- -------------
  **Day of    **Week 1** **Week 2** **Week 3** **Week 4** **Week 5** **Average**
  Week**                                                             

  Sunday                 2766       2229       2203       2210       2352

  Monday                 6054       5517       5619       5425       5654

  Tuesday                6550       6263       6253       6020       6272

  Wednesday              6643       6368       6204       6219       6359

  Thursday    6520       6465       6318       6207       5640       6230

  Friday      5712       5250       5211       5071       4157       5080

  Saturday    2674       2208       2081       2077                  2260
  ----------- ---------- ---------- ---------- ---------- ---------- -------------

Source: Michigan Department of Transportation, Blue Water Bridge

From discussions with the Michigan Department of Transportation and the
Blue Water Bridge Authority, it was learned that backups typically did
not occur on the U.S. side and, when they did, they did not grow very
long. However, on the Canadian side, backups occurred on a regular basis
and could stretch for many miles along Highway 402. On the Canadian
side, the backups could occur as early as 8 am.

**Data Collection Procedures**

The data collection stations selected for the crossing were chosen
because of the particular actions that occur at each site. Segments
defined by the data collection stations were used to determine the
commercial vehicle travel times and freight delay. As illustrated in
Figures 3 through 8, the data collection sites were located at:

-   An advance station located upstream of the commercial vehicle queue
    -- OB-1 and IB-1.

-   The import station (primary inspection booths before detailed, or
    secondary, inspection) -- OB-2 and IB-2.

Data collection was conducted by recording commercial vehicle license
plates as vehicles crossed fixed points within the data collection
sites. Survey individuals or teams, were placed at each of the four data
collection sites to record commercial vehicle license plate data.
Figures 3 and 4 contain diagrams of the facilities on both sides of the
border, including station locations and major points of inspection.

Collectors at these locations would record the last five characters of
the front, lower-left license plate of as many trucks as possible that
passed their location. When trucking firms register many vehicles at
once, they often get assigned sequential license plate numbers. Using
the last five characters helps to ensure that as different trucks
operated by the same firm travel across the bridge that they are
uniquely identified. License plate information was entered into
Handspring Visor PDAs (handheld computers) with a special application
designed for this project. Each entry was time-stamped with the current
date and time. Prior to each day's collection, all PDAs were
synchronized to the same time. Prior experience indicated that recording
the entire license plate was too time consuming and that entering only
the last four characters did not provide adequate distinction between
different vehicles, so the project team chose to record the last five
characters.

Typically, the queue of trucks crossing the border would not extend
beyond the bridge plaza. However, on occasion the queue would extend
onto the highway system. When this occurred, the data collector at the
#1 location would have to move further from the bridge to a point beyond
the end of the queue. In this way, they could continue to record trucks
before they began their wait at the end of the line. When this or any
other event of interest occurred, the collectors would use an "EVENT"
feature of the PDA software to record it.

For each #1 location, the supervisor would record the distance from any
data collection point other than the original position (which would be
in the bridge plaza). During post-processing, the data from all
locations nearer to the bridge than the *farthest* location would be
adjusted to include the additional travel time from the farthest
location to the original location. The travel time would be computed at
free-flow speeds, since there would have been no queue at the times that
the data were collected at these closer locations. In this way, the data
all would appear to be collected from the same location, the one most
distant from the bridge.

The data collection team used both cell phones and hand-held, two-way
radios to maintain in touch with each other. This was particularly
important when the queues lengthened such that a collector had to move
farther upstream. The supervisor could be kept informed without repeated
trips to each data collection location. This was also useful at the end
of the day when the #1 collectors would inform the #2 collectors of the
last truck they recorded, so the #2 collectors would know when to stop.
While interference and cell tower locations created some problems with
reception, each collector was usually able to use either their radio or
cell phone to reach whomever they needed to speak with.

**Data Collection Sample Size**

Sample sizes are typically not a concern with videotape or handheld data
entry devices, because the data collection includes a large number of
vehicles. However, minimum sample sizes should be verified with
variability values from field data. Early research found that sample
sizes from 25 to 100 license matches were necessary for a given roadway
segment and time period (Turner, et. al.). In all but one case at the
beginning of a day of collection, there were sufficient records *each
day* to meet this requirement.

**Data Collection Equipment**

### 

As outlined in the "Data Collection Procedures" section above,
Handspring Visor PDAs were used as the data entry device and proved
adequate to the task. Low-end models with 2 Mb of storage capacity were
selected as the application and data size were projected to be well
below this limit. The Handspring Visors use the Palm OS (operating
system) and have faster processing speeds (at least in side-by-side
comparison with this application) and larger screen sizes than
comparable models from Palm Computing.

A custom application was developed for the Palm OS that allowed the data
collectors to identify their locations (e.g., OB-1, IB-2), the number of
open booths (primarily used for the customs inspection booths), special
events or other comments, and license plate information. A screen shot
of the application interface is shown in Figure 9.

![](media/image10.png){width="3.125in" height="3.3125in"}

**Figure 9. Data Collection Device and Software Application**

The data were downloaded via a serial cable directly from the
application into a text file on the field laptop computer, which was a
Dell Latitude CPx H running with a 500 MHz Pentium III processor.

**Data Collection Summary**

Table 6 shows the number of commercial vehicle license plates recorded
for each of the stations on each of the data collection days. Table 7
shows the average daily traffic volume as recorded by the Blue Water
Bridge Authority (inbound direction) and the Michigan Department of
Transportation (outbound direction). Hourly volumes are used in the
calculation of delay; those are shown with the delay calculations in
Tables 8 through 19.

**Table 6. Number of Commercial Vehicle License Plates Collected**

  ------------- ------------- ------------- ------------- ------------- ------------- -------------
  **Station**   **6/12/01**   **6/13/01**   **6/14/01**   **8/14/01**   **8/15/01**   **8/16/01**

  OB-1          1470          1712          1695          1334          1592          1656

  OB-2          1545          1858          1841          1445          1669          1655

  IB-1          1396          1745          1550          1469          1623          1461

  IB-4          1679          1800          1695          1584          1787          1556

  Total         6090          7115          6781          5832          6671          6328
  ------------- ------------- ------------- ------------- ------------- ------------- -------------

**Table 7. Average Daily Traffic at the Blue Water Bridge**

  --------------- ------------- ------------- ------------- ------------- ------------- -------------
  **Direction**   **6/12/01**   **6/13/01**   **6/14/01**   **8/14/01**   **8/15/01**   **8/16/01**

  Inbound         3335          3305          3029          3056          3041          2771

  Outbound        2626          2981          2973          2668          2768          2844

  Total           5961          6286          6002          5724          5809          5615
  --------------- ------------- ------------- ------------- ------------- ------------- -------------

##### **Data Quality Steps**

At the end of each day of data collection, the supervisor would collect
the PDAs and download the data into the field laptop computer where it
was stored on the hard drive. The data would be examined for any
anomalies and transferred across the Internet to a secondary location
for backup purposes. The OB-1 and OB-2 data would be merged together and
license plates from the two locations would be "matched" using a
spreadsheet developed in Microsoft Excel. As it is easy to mistake
certain characters, particularly letters that looked like numbers, the
license plate data was pre-processed. All 'I's were replaced with '1's;
all 'O's, 'D's, and 'Q's were replaced with '0's; all 'S's were replaced
with '5's; and all 'Z's were replaced with '2's. In addition, the data
collectors were instructed to always use '1's for 'I's and '0's for 'O's
(i.e., to use the digit, rather than the letter).

Occasionally, collectors would be unsure about a license plate and would
append "QQQ" to their entry. This would typically occur when several
trucks passed the collector in rapid succession or if one truck blocked
the license plate of another and he or she could only manage a quick
glimpse. This would allow the supervisor to search the downloaded data
for a potential match by using the travel times of other trucks that
were recorded in the same general time frame. During this process, the
supervisor could also identify the few records in which the data
collector forgot to press "ENTER" after recording a license plate before
recording the next one. These ten-character entries could be split into
two and the time for the first interpolated from the adjacent entries if
they were less than a minute or so apart.

Data post-processing also included a step to identify any anomalies in
the data, including outliers. Outliers, records that indicated travel
times significantly greater than typical for that time period, were most
often caused by recording the license plate of a vehicle only some of
the time as it made repeated trips across the border during a single
day. This is because the matching algorithm uses the most recent time at
the #1 position when matching to a record from a #2 location. For
example, if the vehicle was recorded as it headed from Canada to the
U.S. early in the morning, later returned to Canada, was missed as it
re-entered the U.S. later in the day, and then recorded on its
subsequent return to Canada, the #1 time from its first trip would be
matched with it #1 time from the first trip (for a valid travel time) an
also matched to the #2 time from its second trip (an invalid travel
time). This invalid travel time would be easily identified by manual
inspection of the data, aided by highlighting those travel times above a
specific, but variable, threshold.

## Freight Delay Analysis

The measure for the freight transportation system at international
roadway border crossings is travel delay per truck trip through the
first inspection point in the import country. Delay is measured relative
to the travel time at low volume conditions, which will allow the
processing time of the inspection to be accommodated outside of the
measure. Estimating the average delay per truck for each hour where
congestion is present and then applying the average hourly truck volume
produces an estimate of total delay.

The average delay per truck for each hour is the difference between the
travel time at low volume conditions and the travel time each hour.
Travel time is also affected by the number of open inspection booths and
this information was recorded on all days as it changed. To determine
the average travel time for each road segment, the matched license plate
data in the database is used. The number of matches are noted for
statistical analysis and the travel time is noted for each hour. The
travel time for each truck was assigned to the hour when they passed
through the primary customs inspection location as this was the only
location that remained consistent throughout the data collection. It
should be noted, however, that the hourly volumes are obtained from the
bridge operators and are measured at the toll booths.

The data are presented in Tables 8 through 19. The columns illustrate
the key elements for estimating delay:

-   No Delay Travel Time -- The time through the system at low volume
    conditions. For this report, the value used was that of the lowest
    hourly travel time in that direction for each three-day data
    collection period.

-   Average Number of Open Booths -- The average number of primary
    Customs commercial vehicle inspection booths open and available for
    processing trucks. This figure is not used to compute delay but is
    useful to help understand the relationship between booths, traffic
    volume, and delay.

-   Number of Matched Vehicles -- The number of vehicle observation used
    to estimate the travel time for each hour.

-   Average Travel Time -- The amount of travel time from entry to exit
    for trucks entering the system each hour (use the time the vehicle
    passes the advance point as the determinant of the time period
    label).

-   Delay per Trip -- The difference between the average travel time and
    the "no delay" time.

-   Average Traffic Volume -- The average hourly truck volume for the
    "season" or time of year being analyzed.

-   Total Delay -- The product of the hourly truck volume and delay per
    trip.

Table 8. Total Delay -- 6/12/2001 -- Outbound

![](media/image11.wmf)

Table 9. Total Delay -- 6/13/2001 -- Outbound

![](media/image12.wmf)

Table 10. Total Delay -- 6/14/2001 -- Outbound

![](media/image13.wmf)

Table 11. Total Delay -- 8/14/2001 -- Outbound

![](media/image14.wmf)

Table 12. Total Delay -- 8/15/2001 -- Outbound

![](media/image15.wmf)

Table 13. Total Delay -- 8/16/2001 -- Outbound

![](media/image16.wmf)

Table 14. Total Delay -- 6/12/2001 -- Inbound

![](media/image17.wmf)

Table 15. Total Delay -- 6/13/2001 -- Inbound

![](media/image18.wmf)

Table 16. Total Delay -- 6/14/2001 -- Inbound

![](media/image19.wmf)

Table 17. Total Delay -- 8/14/2001 -- Inbound

![](media/image20.wmf)

Table 18. Total Delay -- 8/15/2001 -- Inbound

![](media/image21.wmf)

Table 19. Total Delay -- 8/16/2001 -- Inbound

![](media/image22.wmf)

As previously mentioned, the number of open primary Customs inspection
booths was also recorded. Examining the previous tables shows the
relationship between the volume of trucks moving across the border and
the number of open inspection booths on the travel times, particularly
in the inbound direction.

At the Blue Water Bridge, data collectors did not have to relocate due
to an increasing queue length in the outbound direction, but did have to
move in the inbound location. Several different locations along Highway
402 were chosen, depending on the current conditions. Of course, it was
the easiest to record data at the initial location in the Canadian plaza
as trucks approached the bridge. Here, they were moving slowly and were
most often using only the rightmost lane. Two alternate locations were
at or near the Indian Road interchange on Highway 402, approximately 1.4
and 1.8 miles from the initial location, respectively. Here, trucks
would pass at highway speeds and would often use both lanes, reducing
the number of vehicles that could be effectively recorded. Two
additional locations were used when the trucks backed up beyond the
Indian Road interchange. The first was at the Airport Road interchange,
approximately 5.2 miles from the initial location. This area was in the
construction zone and traffic was limited to a single lane. While
vehicles still passed at full highway speeds, data collection was easier
than at Indian Road due to the single lane of traffic. During the final
days of data collection, the location was moved the next overpass closer
to the bridge (0.55 miles closer than the Airport Road location) because
of construction activity at the Airport Road interchange. On one
occasion, the queue actually approached within a half mile of the
adjusted Airport Road location. On another, the queue was approximately
4 miles long.

Specifically, the IB-1 collector had to move from the initial location
around 2:25 pm on 6/12/01 upstream from the bridge. By approximately
2:40 pm, the queue had passed the Indian Road location and the collector
had to move to Airport Road. This illustrates how quickly the queue can
grow. That day, the collector remained at Airport Road until shortly
after 4 pm. There was no queue the entire day on 6/13/01. On 6/14/01,
the IB-1 collector moved to Indian Road at around 5:40 and then to
Airport Road just before 6 pm. The queue had not yet dissipated by
around 9:30 pm when data collection was stopped for the day.

The queue situation was different during the second week of collection.
The IB-1 collector began collection at Indian Road at 6:30 am on
8/14/01. Approximately 12:45 pm, the collector moved to the alternate
Airport Road location and remained there until the end of the day at
6:30 pm. Also, at around 8:30 am on 8/14/01, there was some construction
activity on the roadway in one of the U.S. Customs primary inspection
booths. This involved a significant amount of jackhammering and the
adjacent booth was also closed because of the noise was too great for an
inspector to function effectively. There were significant queues heading
into the U.S. that day and the other three available booths were open
for most of that time; however, it is unclear whether a fourth or fifth
booth would have been opened if the construction were not taking place.

The queues continued on the second day of week two collection, 8/15/01,
with the IB-1 collector again beginning at Indian Road (at 9:30 am).
However, at 1 pm, the queue completely dissipated and the collector was
able to return to the initial location on the bridge plaza. For the
first time, however, the auto traffic began to interfere with the
commercial vehicle traffic. As mentioned previously, trucks typically
use the left two lanes when approaching the primary inspection booths
and cars use the right lane. On this day, there was such an increase in
auto traffic that impatient drivers were also occupying the center lane
and once in a while a car would move into the far left lane. On three
occasions between noon and 1:30 pm, the backup of cars extended from the
auto inspection booths onto the bridge in all three lanes. This
completely blocked truck traffic to the commercial lanes and would
result in all the open truck inspection booths being empty for at least
five to ten minutes until the next truck in line could pass by the cars
in front of it. Also on 8/15/01, a truck became disabled in one of the
open booths at 1:37 pm and was not towed away until 2:24 pm.

On 8/16/01, the IB-1 data collection began at Indian Road at 9:15 am and
remained there until almost 10:30 am. However, the bridge remained
fairly full of trucks and again there were a significant number of
passenger cars. These cars temporarily blocked the trucks from
approaching the inspection booths on three occasions, around 4:00, 3:45,
and 4:40 pm.

For all days of data collection except the last (8/16/01), there were no
weather conditions of note. However, there were alternating periods of
light and heavy rain for most of the last day of collection until
approximately 5 pm. Of particular issue, however, was the difficulty in
reading license plates beginning at early dusk. While the locations near
the bridge facility provided ample lighting, the illuminated headlights
of approaching trucks effectively blinded the data collectors until the
split second before the truck passed their location. This proved
particularly difficult for the IB-1 collector who was recording trucks
passing in excess of 60 miles per hour. The binoculars that all data
collectors used to some degree made the glare even more pronounced.

The chosen locations for data collection proved to be well suited to the
task. On several occasions, it would have been helpful to have specific
written (rather than verbal) authorization from the local Canadian
Immigration officials to facilitate processing at the primary auto
Customs inspection as we entered Canada. On two occasions, the e-mail
from the Vice Consul was insufficient for the Customs inspector and our
staff were instructed to speak with the Immigration officials, "just to
check". On both occasions, the Immigration staff were aware of our study
and cleared us for entry, but we were nonetheless delayed. After the
first occasion (our first pre-collection reconnaissance of the site), we
requested some form of written documentation from Canadian Immigration
and were told that we should not have any further problems, as they were
aware of our study. On the second occasion, a Customs shift supervisor
forgot to mention our presence to the morning shift of inspectors, which
caused the delay.

## Statistics

Table 20 shows the baseline or "no delay" travel time, the average
travel time, and three other measures that indicate the reliability of
the travel time estimates. The baseline time (in minutes) is the time
needed to travel the study distance (between the starting point in the
exporting country and the initial inspection point in the importing
country) in free-flow traffic conditions. The average time is computed
from all vehicles measured during the data collection period over the
study distance. The 95^th^ percentile time is the time (in minutes)
within which 95 percent of all trucks can cross the border. The buffer
time is the additional time above the average crossing time (in minutes)
that it takes for 95 percent of all trucks to cross. The buffer index
expresses the buffer time in terms of the average time and is the
percentage of extra time that must be budgeted to cross the border
within the 95^th^ percentile time. For example, if the average time was
10 minutes and the buffer time was 5 minutes, the buffer index would be
50 percent.

Table 20. Crossing Times

+----------+-----------+----------+----------+----------+-----------+
|          | Baseline  | Average  | 95^th^   | Buffer   | Buffer    |
|          |           | Crossing | Pe       | Time     | Index     |
|          | Time      | Time     | rcentile |          |           |
|          |           |          | Time     |          |           |
+----------+-----------+----------+----------+----------+-----------+
| Outbound | 5.0       | 6.2      | 9.1      | 2.9      | 46.8      |
+----------+-----------+----------+----------+----------+-----------+
| Inbound  | 11.1      | 34.2     | 80.3     | 46.1     | 134.8     |
+----------+-----------+----------+----------+----------+-----------+

From the table, it is apparent that both the average travel time and the
reliability are significantly more favorable for outbound traffic than
for inbound traffic.

Figure 10 illustrates the average travel time experienced for different
truck volumes per lane per hour in each direction.

![](media/image23.wmf)

Figure 10. Average Travel Time for Different Hourly Volumes

Figures 11 and 12 show typical average hourly traffic volumes per booth
for the study period as well as the measured average hourly travel
times. In addition, the average number of open primary Customs booths in
each direction is shown.

![](media/image24.wmf)

Figure 11. Typical Inbound Traffic

## 

![](media/image25.wmf)

Figure 12. Typical Outbound Traffic

## Conclusions

Lessons learned during data collection activities in this project at
this site and at others along the Canadian and Mexican borders with the
U.S. have identified several issues that should be taken into
consideration to assist future data collection efforts. Some apply to
advance planning and the initial site visit and others apply more
specifically to the data collection activities themselves.

[Planning and Site Visits]{.underline}

-   Prior to conducting any data collection project, all jurisdictional
    and cooperating agencies should be made explicitly aware of the
    purpose and objectives of the study as well as all the details
    associated with the data collection project (e.g. dates, times,
    procedures to be followed during the data collection period, etc.).
    Failure to do so may result in confusion and possible delay of the
    study. This has been very time-consuming at some ports and should be
    adequately accounted for in the schedule. For some agencies,
    including U.S. Customs, it is important to contact both the federal
    and local levels. Some entities that should be contacted might not
    be readily apparent and can include construction companies working
    on public rights-of-way, state police, city officials, and Thruway
    Authorities. Some agencies provide verbal approval for the data
    collection and may even provide supporting documentation to their
    field staff, yet are reluctant to provide documentation for the data
    collectors to carry. Every effort should be made to obtain written
    authorization that can be carried by the data collectors,
    particularly from bridge authorities and immigration officials.
    Several times at some sites, the officer at the primary auto
    inspection booths asked data collectors to go to secondary
    inspection and speak with immigration officials. Although allowed to
    continue, this caused some unnecessary delay in the data collection.

-   Prior to data collection activities, a general idea of traffic peak
    periods and conditions should be understood to optimize collection
    of appropriate traffic data and coverage of the appropriate times.
    This information should be obtained from discussions with
    knowledgeable officials and by examining historical traffic data.

-   Any additional data needs should be discussed explicitly with the
    appropriate officials. At some crossings, for example, average
    hourly truck volumes are not normally recorded and maintained, but
    can be if special arrangements are made in advance. Alternatively,
    it may be appropriate to use other means to measure truck volumes,
    such as roadway counters or having the data collectors indicate the
    vehicles that pass without their license plates being recorded
    (assuming continuous data collection during each day). These
    additional traffic volumes could be used to corroborate data
    provided by the local authorities or used if their planned data
    collection did not occur or there was some other problem in
    providing the data.

-   It is also important to be aware of special federal or local
    holidays on both sides of the border when scheduling data
    collections as these could affect traffic flows. Some minor holidays
    that occur on Mondays and Fridays, might not significantly affect
    traffic for a Tuesday through Thursday data collection period, but
    may increase the likelihood that key local officials will be on
    vacation and unavailable should any problems arise.

-   When scheduling the data collection times, consider the availability
    of sunlight or high-powered lighting. It becomes increasingly
    difficult to read license plates at night as trucks approach with
    their headlights on (also a problem during rain) and entering the
    data into the PDAs also becomes more difficult when it is dark.

-   Photographs of the border facilities and data collection locations
    should be taken during the site visits to assist in documenting the
    collection effort and to better inform the data collectors prior to
    their arrival on-site.

-   Processing, data quality, and analysis of all traffic data require
    the largest portion of the study time.

[Data Collection Activities]{.underline}

-   Prior to data collection activities, an explanation and
    understanding of the procedures to be followed and logistics should
    be made clear to all members of the study team (e.g., number and
    location of license plate characters to be recorded, all commercial
    vehicles should be recorded, when and how to contact the on-site
    supervisor, etc.).

-   Proper identification for all survey members and written
    documentation of authorization from all jurisdictional agencies
    should be carried at all times by all members of the study team,
    especially when conducting business in a foreign country.

-   The supervisor should assess all conditions upon arrival for data
    collection to note any changes from the site visit or prior
    collection activities. Sometimes unplanned construction or other
    events may alter the preferred data collector locations or the truck
    flow patterns.

-   While only one supervisor was originally planned for each data
    collection visit, it was determined that installing one supervisor
    on each side of the border was highly desired. One supervisor would
    be designated the overall site supervisor. This presented several
    benefits, the most important being added safety and security for the
    data collectors, particularly for a collector who needed to move to
    a remote location upstream from the border when the queue extended
    beyond their original location. Other benefits were increased
    awareness of current conditions and the origin of backups, the
    increased ability to relieve data collectors for breaks and lunch
    while maintaining continuous data collection, and assisting with
    data collection during exceptionally high-volume times or in
    difficult locations (such as remote spots along a highway when the
    vehicles were passing at free-flow speeds). Without the extra
    supervisor, a single supervisor would make repeated trips across the
    border to check on the collectors, relieve them, and provide them
    with food and drink if they were not conveniently located nearby.
    Border delays would often make this an extremely time-consuming
    process.

-   For Mexican data collection, it is recommended that Mexican
    nationals be used, both as supervisors and as data collectors. This
    helps to enhance coordination with national, state, and local
    officials and to minimize the likelihood of immigration or other
    problems with federal, state, or local agencies.

-   As mentioned above, the supervisors should be used to maintain
    nearly constant data collection during breaks. This improves data
    quality by ensuring the supervisors repeatedly observe each
    collector and can identify and correct any problems they might be
    having. Further, this improves the number of trucks matched at both
    the #1 and #2 locations, improving the sample size for analysis.

-   Communication between the data collectors and their supervisors is
    crucial to an efficient and successful effort, particularly when one
    of the data collectors must move upstream past the end of a growing
    queue. Communication with the supervisor is also important when a
    data collector is having a problem with an official questioning
    their authority to do their work or when some other unexpected event
    occurs. For example, occasionally, there may be an anomaly with the
    data collection equipment and the collector can receive immediate
    instructions on how to proceed rather than having to wait until the
    supervisor next visits their location. Two-way radios (FRS-type with
    up to a two-mile range) and cell phones work adequately in most
    situations, but interference and range can limit their
    effectiveness. Cell phone service can be spotty near border areas.
    Additional longer-range communication options that do not require
    FCC approval should be considered for future collections. Obviously,
    when using cell phones, ensure that long-distance charges and
    roaming fees will not be significant costs.

-   It is important to ensure that the data collectors are safe and
    comfortable during their long periods of collection. If their data
    collection locations cannot provide adequate cover from severe rains
    or heat, additional vehicles should be considered. Comfortable sport
    chairs with attachable beach umbrellas served to protect the
    collectors well during light rain and moderate sun. Ensure that the
    collectors have an adequate supply of water and that facilities are
    conveniently accessible. This becomes more difficult for the remote
    locations upstream from the border crossing.

# REFERENCES

Turner, S.M., W.L. Eisele, R.J. Benz, and D.J. Holdener. *Travel Time
Data Collection Handbook.Report.* No. FHWA-PL-98-035. Federal Highway
Administration, Texas Transportation Institute, March 1998