![](media/image1.png)

Final Site Report

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

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

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

**[Monitoring]{.smallcaps}**

**[Ambassador 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 -- Ambassador Bridge**

## **Site Description**

The Ambassador Bridge is a large, imposing structure that connects
Detroit, Michigan and Windsor, Ontario (see figures 1 and 2). The bridge
is the single busiest international land border crossing in North
America, serving as a portal for 27% of the approximately \$400 billion
in annual trade between Canada and the U.S. The bridge is 1.6 miles long
from tollbooth to primary inspection checkpoint in either direction. The
roadway is four lanes whose directional flow is controlled by overhead
changeable electronic lane markers, often in combination with cones. The
bridge operates 24 hours per day, 7 days per week. It facilitates the
movement of many commodities between the U.S. and Canada, with the
automotive industry being the most notable.

![](media/image2.png)

#### Figure 1. Area Map -- The Ambassador Bridge.

Both trucks and autos intermingle in the same lanes as they cross, then
on the far side they separate into discrete lanes as they approach
separate primary checkpoints, in both the U.S. and Canada. After primary
inspection, trucks and autos mix as they exit Canadian Customs into
Windsor, while trucks that exit U.S. Customs are segregated from autos.
The Windsor-Detroit Tunnel is only a short distance away. The tunnel is
for autos only, one lane in either direction.

There is a sidewalk on the south side of the bridge only. One lane of
the bridge near the middle is typically closed for a long-term bridge
cable-painting project. During painting operations, traffic is typically
funneled into 3 lanes by cones for about three hundred yards. When the
painting is being done on the south side of the span, the sidewalk helps
to accommodate equipment and decrease the length of the lane that is
cordoned off for painting (see figure 2).

![](media/image3.jpeg){width="4.444444444444445in"
height="2.1395833333333334in"}

**Figure 2. Maintenance Equipment on Ambassador Bridge.**

On the U.S. side, the bridge is located beside I-75 near its
intersection with the eastern terminus of I-96. The bridge crosses only
two miles south of downtown Detroit. Since space is at a premium as a
result of the developed urban/industrial setting, trucks approaching the
U.S. side must make an abrupt, tight 180-degree turn to enter primary on
the U.S. side. Trucks on the Canadian side have more room for a
straightforward approach to primary and, as will be explained, secondary
inspection is not located at the same facility. The bridge entrance/exit
on the Canadian side is in a less industrial setting next to the campus
of the University of Windsor. Truck traffic exits onto Highway 3 (Huron
Church Road), which after 5-1/2 miles intersects Highway 401, a major
route that heads northeast across Ontario.

The bridge and its collateral facilities are privately owned and
operated by the entity known as the Ambassador Bridge. The mission of
the Ambassador Bridge is to operate and maintain the bridge and collect
tolls on both sides of the crossing. The Ambassador Bridge's U.S. owner
is the Detroit International Bridge Company and its Canadian subsidiary
is The Canadian Transit Company. Ambassador Bridge owns the facilities
that house Canada Customs and Immigration while GSA owns the U.S.
Customs facility. Since Ambassador Bridge owns and operates the property
that the tollbooths are on, the data collectors who were located by the
toll collection booth in either country had to have permission from
them, which was verbal.

The U.S. and Canadian Customs mission is to protect their border. They
operate the facilities and control the property where their Customs
facilities are located. Data collectors who were operating beside the
primary Customs checkpoint in either country had to have permission to
be on property operated by the Customs organization of that country.
Thus on both sides of the crossing, even though that collector was only
a very short distance from the collector at the tollbooth, the approval
to operate at that spot came from a different organization.

Ambassador Bridge employees included three to four persons assigned to
handle traffic on each side. If an accident on the bridge is minor,
bridge personnel take pictures quickly and then move the vehicles. While
the Ambassador Bridge's needs are clearly different from the needs of
the U.S. and Canadian Customs organizations, all parties appear to
cooperate effectively with one another. For example, if some unusual
event causes sudden and severe backup (which the data collection team
observed once in particular), the Customs organizations responded by
manning extra booths to help restore normal flow across the border.
Also, for example, on the second day (Wednesday) of the second data
collection period, a truck ran out of fuel on the bridge heading to
Canada around 5:00 P.M. It sat for about an hour restricting traffic
until it could be moved. Bridge personnel held up traffic headed to the
U.S. so traffic headed for Canada could cross during part of the time
that the truck was blocking traffic. But in normal operation, delays
introduced by Customs operations have a greater impact on Ambassador
Bridge operations than vice-versa. Lines are painted on the road
occasionally. A quick-drying plastic compound is used so that traffic
holdups are minimal. Ambassador Bridge personnel held up traffic at the
IB-2 tollbooth for approximately ten minutes during the first
collection.

Data collection activities at the Ambassador Bridge occurred during May
22-24, 2001 and June 19-21, 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. Anecdotally, Canada Customs is said to have typically four lanes
open during a weeknight and three lanes on a weekend, while and U.S.
Customs has two to three lanes open during weeknights and one lane
during weekends.

**Canada-bound Traffic.** For trucks heading into Canada, the connecting
roadway system leading to the bridge is somewhat complex. The majority
of trucks exit off of I-75 northbound and southbound, where they have to
proceed along a service road -- Fisher Freeway -- a short distance to
access the bridge. Rush hour traffic can cause this line of trucks
(along with autos) to back up onto the right lane of the Interstates,
particularly I-75. The trucks on Fisher Freeway that have exited from
I-75 southbound have to make a sharp left turn to cross the Porter
Street overpass, then turn right to access the bridge entrance at a very
busy intersection that has multiple connecting roads. A smaller number
of trucks arrive directly at the same intersection by the bridge
entrance via a feeder route that connects to the nearby eastern terminus
of I-96.

On the other side on the Interstate (the east or bridge side), some
trucks and autos that have exited from I-75 northbound onto Fisher
Freeway pull into the main duty-free area instead of proceeding the
short distance to the bridge entrance. Trucks and autos exit from
duty-free via the "west ramp" through two tollbooths which process both
autos and trucks, then they make a sharp turn separated by barricades
from the main bridge traffic to enter the flow across the bridge. The
outbound trucks and autos that pass by the duty-free entrance on Fisher
Freeway northbound make a sharp right turn after about two hundred yards
onto the bridge at the complex intersection described above.

Some trucks, particularly those that have exited from I-75 southbound or
I-96, pull over to the right at the bridge entrance and park to visit a
small duty-free store just prior to the car/truck tollbooth entrance on
U.S. side. This impromptu parking area was beside one of our data
collection stations (see figure 3). Drivers who visit this duty free
store walk across often-heavy car and truck traffic to reach the store,
and then walk back to their parked trucks a few minutes later to proceed
into Canada. Autos tend to pull over in a similar manner on the other
side of the flow, next to the duty free store. All vehicles whose
drivers have used any duty free store must proceed across the bridge
into Canada.

![](media/image4.jpeg){width="4.444444444444445in"
height="2.9430555555555555in"}

Figure 3. Some drivers park their trucks and cross

traffic on foot to reach a duty-free store.

The main truck flow across the bridge into Canada proceeds through four
truck-only tollbooths in addition to the two truck/car tollbooths on the
"west ramp," for a total of six tollbooths used by trucks. There are
eight tollbooths reserved for autos that are to the left of, and
adjacent, to the four main truck-only booths. Autos and trucks are mixed
as they enter the bridge and some have to veer across several lanes of
traffic to get to the appropriate tollbooths.

Once across the bridge and in Canada, autos are directed to the left and
trucks to the right to pass through one of the primary Customs
inspection booths. There is a bank of twenty Canadian primary booths --
ten on the left that process autos only, and ten on the right that can
process autos or trucks (see figure 4). Canada shifts employees at the
primary booths at 5 minutes to the hour -- gates come down and hold
traffic. Trucks are either released from primary or must continue on to
secondary inspection, which could include completing brokerage paperwork
or physical inspection of the cargo. An occasional truck is directed to
a special covered inspection area adjacent to primary, but most trucks
that are directed to secondary inspection proceed onto Huron Church
Road, which becomes Highway 3 through Windsor.

![](media/image5.jpeg){width="4.444444444444445in"
height="2.0131944444444443in"}

Figure 4. Primary at Canadian Customs, Windsor side.

A unique feature of Canadian Customs at the Ambassador Bridge is that
their secondary inspection is not located at the same facility as
primary inspection, but rather is located over a mile and a half from
primary inspection off Huron Church Road. Truck drivers who are told at
primary that they must go through secondary inspection will proceed to
the secondary inspection facility on the honor system (although of
course there are stiff penalties for anyone who does not comply).
Canada, therefore, permits trucks that require additional inspection or
other scrutiny to proceed into the country and onward to the remote
secondary inspection site where the issues will be addressed. This is in
sharp contrast to the U.S. Customs operations where a truck with
brokerage issues is not permitted to leave the Customs compound until
all issues are resolved.

The area immediately past Canadian primary (the bank of twenty stalls
for both autos and trucks) sometimes becomes extremely congested through
a combination of very heavy traffic and the geometry of traffic flow.
The exits from primary are directly past where the truck stalls are
located; they include three lanes straight onto Huron Church Road
outbound (i.e., southbound; Windsor is geographically south of Detroit)
and a curving ramp of two lanes onto Huron Church Road northbound (but
this is not the road that crosses the bridge). When exiting from
primary, autos have to proceed to the right almost perpendicular to
truck flow (see figure 5), especially if the autos intend to exit onto
the two-lane ramp for Huron Church Road northbound.

As traffic builds up, the likelihood increases that a car heading for
the Huron Church Road outbound exit ramp will cut in front of a truck
that is accelerating out of a booth in primary. The data collection team
observed a couple of occasions when this area just past the primary
booths had filled up so completely that there were about as many
vehicles as close together as the area could possibly hold. This
occurred because both autos and trucks were leaving the primary booths
at a greater rate than they could exit onto the road system. When it
reached this point, trucks started to be held at the primary booths.

![](media/image6.jpeg){width="4.444444444444445in"
height="3.3333333333333335in"}

Figure 5. Rare congestion below Canadian Customs booths.

There is a railroad line that crosses Huron Church Road beside College
Avenue, only 200 yards or so past primary and perhaps 400 yards upstream
from the tollbooth. During the three days of data collection, trains
were observed crossing several times a day, stopping traffic for an
average of three to four minutes each time. This was of sufficiently
short duration that it did not appear Canadian Customs needed to hold
traffic at the tollbooths.

U.S.-bound Traffic.

The majority of traffic crossing to the U.S. comes from Huron Church
Road/Highway 3, which terminates at the Ambassador Bridge. Just past the
intersection of Huron Church Road with College Avenue and the railroad
track, signs direct autos to the left and trucks to the right.
Immediately past is another split, dividing local traffic and truck
traffic crossing the bridge (see figure 6). Trucks wanting to enter the
duty free area exit to the left about two hundred yards past the
auto-truck split, into the commercial vehicle duty free parking. Trucks
exiting the duty free area merge with the main truck traffic about one
hundred yards past where they entered duty free, then they proceed to a
bank of five truck tollbooths. When leaving duty free, they merge with
the traffic flow on the truck side merge with autos after the
tollbooths, and cross the bridge.

![](media/image7.jpeg){width="4.444444444444445in"
height="2.276388888888889in"}

Figure 6. Truck inbound to U.S. approaching tollbooths on

Canadian side. Data collector can be seen in background.

There is also an entrance ramp coming up from Wyandotte Street West in
the vicinity of the University of Windsor campus that enters the bridge
approach across from the duty-free store exit. There are two tollbooths
processing both trucks and autos on this ramp. The trucks and autos that
exit this ramp are retained in the right hand lane by cones and barrels,
separated from the main truck flow for about one hundred yards until
they pass the line of tollbooths and merge.

Once across the bridge and in the U.S., autos are directed to the left
and trucks veer off to the right to pass through one of the primary
Customs inspection booths. As mentioned, trucks approaching the U.S.
side must work their way into the right lane and make an abrupt, tight
180-degree turn to enter primary on the U.S. side. While the turn is
two-lane, its geometry forces trucks to travel single-file. Then the
trucks' approach straightens out and they enter a bank of six primary
booths (see figure 7).

![](media/image8.jpeg){width="4.444444444444445in"
height="2.6930555555555555in"}

Figure 7. Primary at U.S. Customs, Detroit side.

Trucks released from primary drive straightforward one hundred yards to
a traffic light and "T" at the intersection of Fort Street, where they
must turn left or right. Trucks requiring physical inspections or who
need to visit customs brokers veer off to the right and make a 180
degree turn clockwise around the Customs building and continue into a
large truck parking lot that they circled around on their way into
primary. When trucks are finally ready to depart that lot, they exit via
a designated single lane running through an unmanned booth next to the
customs building. The data collectors below primary were instructed to
not count any trucks exiting from this lane, since these trucks had
induced delay as a result of being in the secondary inspection parking
lot. They merge with the trucks that have been cleared by primary
inspection and use the same exit onto Fort Street to leave the Customs
compound.

Just past primary on the left, before the exit to Fort Street,
construction has begun on a future tollbooth plaza. Concrete has been
poured for tollbooths that will include truck scales, but construction
was interrupted and not in progress at the time of either data
collections. Ambassador Bridge intends to relocate the tollbooth
operation for U.S.-bound traffic from the Canadian side to the vicinity
of primary on the U.S. side.

**Data Collection Process**

For this study, two data collection locations were used in each
direction. The "number 1" location was immediately before the tollbooths
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 with respect to the U.S.). As already
mentioned, movement from Detroit into Windsor is actually southbound;
however, by designating this direction "outbound" confusion is
eliminated. The Outbound 1 (OB-1) position; therefore, is in the U.S.
plaza, before the tollbooths. The Outbound 2 (OB-2) position was after
the Canadian Customs primary inspection booths. Inbound positions (IB-2
and IB-2) were similarly positioned (see figures 8, 9, and 10).

![](media/image9.png){width="7.388976377952756in"
height="5.388976377952756in"}

Figure 8. Layout at the Outbound 1 (OB-1) data collection site on the
Detroit side.

![](media/image10.png){width="6.0in" height="7.902755905511811in"}

![](media/image11.wmf){width="5.7263779527559056in"
height="8.944488188976377in"}

Each data collector used 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.

During both weeks of data collection, the on-site team included four
data collectors and one supervisor. The supervisor provided additional
support to take over data collection when a collector was given a break
or lunch, or sometimes collected supplemental data during a non-typical
event. All four collectors and the supervisor had cell phones, which
worked well at this crossing. The length of the bridge would probably
cause most if not all handheld radios (walkie-talkies) to be ineffective
-- at least, those handheld radios that do not require licenses because
of their lower power.

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.
The supervisor generally brought lunch to the collectors and collected
data at each station so as to allow the collector to take a meal break
or rest break during the data collection, resulting in approximately
12-½ hours of data collection during each of the full days.

## **Table 1. Hours of Data Collection**

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

  5/22/01              12:30 am                  8:00 pm

  5/23/01              8:00 am                   9:00 pm

  5/24/01              6:00 am                   6:30 pm

  6/19/01              9:00 am                   9:45 pm

  6/20/01              6:00 am                   6:40 pm

  6/21/01              5:30 am                   6:10 pm
  -------------------- ------------------------- -------------------------

Obtaining permission was a smooth process. Several separate meetings
were held during a two-day period to secure approval. One meeting was
held on June 7, 2001 with U.S. Customs officials in their facilities at
the bridge, which included their Director of Field Operations, Port
Director, and Chief Inspector. A meeting was held the next day at the
Ambassador Bridge offices on the Detroit side. In attendance were
Ambassador Bridge's General Manager and the ITS Director, who took the
Battelle representative on a tour of all facilities, pointed out logical
sites for the data collectors, and provided introductions to the
District Director of Canadian Customs at his office in the Canadian
Customs building. During these preparatory meetings, the Battelle
representative distributed several key documents (e.g., the project's
explanation, methodology and goals) to help all host organizations
understand our purpose. These helped to facilitate coordination.

Ambassador Bridge talked with the local Canada Immigration Director on
behalf of the Battelle team. The Director determined that -- as visitors
under NAFTA -- the team would not need work permits to collect data on
the premises. Prior to the data collection during both visits, team
members had to obtain visitor's records from Canada Immigration, for
which personal information was provided. During the first visit,
however, the team arrived during Victoria Day (a Canadian holiday that
fell on Monday), which caused a delay in getting final permission and
processing the necessary paperwork until the following day. The team
completed the paperwork on Tuesday morning prior to starting the data
collection, which induced a delay in the first day's start time. During
the second visit, no one on the data collection team except the
supervisor had participated in the first collection, so three of the new
collectors went through that process during Monday. There was no delay
in data collection. Incidentally, this Visitor's Record had the effect
of facilitating the process at primary of explaining why the team needed
to enter Canada via auto.

Other than the formal visitor's records, Canadian Customs required only
a simple visitor's pass from the shift supervisor for the OB-1 collector
for each day of the data collection. Neither U.S. Customs nor Ambassador
Bridge required special passes or other written permission for the team
to work on their premises, only verbal approval. We also contacted the
FHWA Michigan Division to notify them of the nature of the data
collection.

Table 2 contains a list of the individuals who were contacted and their
telephone and e-mail information. With this, 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**    |
+------------------+------------------+---------------+---------------+
| Kevin Weeks      | U.S. Customs     | 313-226-2955  | k             |
|                  |                  | ext. 101      | evin.w.weeks@ |
| Director, Field  |                  |               |               |
| Operations       |                  | 313-226-3118  | cust          |
|                  |                  | (fax)         | oms.treas.gov |
+------------------+------------------+---------------+---------------+
| Angela Ryan      | U.S. Customs     | 313-442-0200  | angela.ryan@  |
|                  |                  |               |               |
| Port Director    |                  | 313-226-3179  | cust          |
|                  |                  |               | oms.treas.gov |
+------------------+------------------+---------------+---------------+
| Ben Anderson     | U.S. Customs     | 313-226-6061  | walte         |
|                  |                  |               | r.b.Anderson@ |
| Chief Inspector  |                  | 313-226-5347  |               |
|                  |                  | (fax)         | cust          |
|                  |                  |               | oms.treas.gov |
+------------------+------------------+---------------+---------------+
| David Jolly      | Ambassador       | 313-967-9816  | amb           |
|                  | Bridge           |               | assgm@att.net |
| General Manager  |                  | 313-967-9818  |               |
|                  |                  | (fax)         |               |
+------------------+------------------+---------------+---------------+
| Joe Polak        | Ambassador       | 313-496-1445  |               |
|                  | Bridge           |               |               |
| ITS Director     |                  | 313-496-1446  |               |
|                  |                  | (fax)         |               |
+------------------+------------------+---------------+---------------+
| David MacRae     | Canada Customs   | 519-257-6491  | David.MacRae@ |
|                  |                  |               |               |
| District         |                  | 519-257-7844  | cc            |
| Director         |                  | (fax)         | ra-adrc.gc.ca |
+------------------+------------------+---------------+---------------+
| Bonnie Brown     | Canada           | 519-971-2030  |               |
|                  | Immigration      |               |               |
| District         |                  |               |               |
| Director         |                  |               |               |
+------------------+------------------+---------------+---------------+
| Morrie Hoevel    | FHWA Michigan    | 517-377-1844  |               |
|                  |                  |               |               |
|                  | Division Office  |               |               |
+------------------+------------------+---------------+---------------+
| Aisha Hall       | Ambassador       |               | Aha           |
|                  | Bridge           |               | llambassador@ |
| statistics       |                  |               |               |
| compiler for     |                  |               | aol.com       |
| Detroit to       |                  |               |               |
| Windsor          |                  |               |               |
+------------------+------------------+---------------+---------------+
| Vicki Winter     | Ambassador       |               | bridgegm@     |
|                  | Bridge           |               |               |
| statistics       |                  |               | wi            |
| compiler for     |                  |               | ndsor.igs.net |
|                  |                  |               |               |
| Windsor to       |                  |               |               |
| Detroit          |                  |               |               |
+------------------+------------------+---------------+---------------+

**Data Collection Details**

Both the Canada Bridge and Tunnel Operator's Association and Ambassador
Bridge provided border crossing statistical data. This data was
evaluated for an assessment of the variability in travel conditions at
the Ambassador Bridge. The goal of this analysis process is to obtain
statistically useful data with as few data collection days as possible.
In order to customize the data collection activities at the Ambassador
Bridge, the following steps were conducted:

-   Define significant "seasonal" variations,

```{=html}
<!-- -->
```
-   Define significantly different days of the week,

```{=html}
<!-- -->
```
-   Identify traffic streams that experience significantly different
    conditions, and

-   Estimate the number of days needed for the data collection survey.

[]{.mark}

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 May and June.

[]{.mark}

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

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

  January          231,614      252,146      289,122      772,882

  February         233,982      267,917      300,190      802,089

  March            262,051      310,562      335,595      908,208

  April            252,893      284,676      287,856      825,425

  May              253,182      291,085      315,227      859,494

  June             252,175      312,437      310,376      874,988

  July             196,751      234,738      224,327      655,816

  August           242,034      306,629      310,658      859,321

  September        258,811      298,182      293,269      850,262

  October          274,318      302,598      309,571      886,487

  November         261,163      300,406      287,644      849,213

  December         274,318      266,775      222,275      763,368

  **Total**        2,995,290    3,430,150    3,488,110    9,907,551
  ---------------- ------------ ------------ ------------ ----------------

Source: United States -- Canada Bridge and Tunnel Operator's Association
Traffic Reports

[]{.mark}

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 15 percent of typical weekday traffic and
Monday/Friday traffic is 59 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 data 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 2001**

  -----------------------------------------------------------------------
  **Day**           **Day of Week**   **Outbound**      **Inbound**
  ----------------- ----------------- ----------------- -----------------
  1                 Friday            6,855             4,925

  2                 Saturday          3,398             2,301

  3                 Sunday            1562              2,541

  4                 Monday            5,373             6,020

  5                 Tuesday           6493              6,399

  6                 Wednesday         6,498             6,289

  7                 Thursday          7,042             5,863

  8                 Friday            6,589             4,700

  9                 Saturday          3,222             2,271

  10                Sunday            1,421             2,280

  11                Monday            4,928             5,725

  12                Tuesday           6,242             6,115

  13                Wednesday         6,432             6,069

  14                Thursday          6,776             5,713

  15                Friday            6,372             4,543

  16                Saturday          3,145             2,155

  17                Sunday            1,379             2,261

  18                Monday            5,039             5,823

  19                Tuesday           6,328             6,224

  20                Wednesday         6,692             6,316

  21                Thursday          6,029             5,518

  22                Friday            6,514             4,683

  23                Saturday          3,257             2,281

  24                Sunday            1,419             2,318

  25                Monday            4,993             5,473

  26                Tuesday           6,149             5,839

  27                Wednesday         6,210             5,837

  28                Thursday          6,617             5,620

  29                Friday            5,827             4,070

  30                Saturday          2,451             1,823

  **Total**                           151,252           137,995
  -----------------------------------------------------------------------

Source: Ambassador Bridge

**Table 5. Averages for Sample Month -- Daily Traffic Distribution of
Export Commercial Vehicles for June 2001**

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

  Sunday                 4,103      3,701      3,640      3,437      3,720

  Monday                 11,393     10,653     10,862     10,466     10,844

  Tuesday                12,892     12,357     12,552     11,988     12,447

  Wednesday              12,787     12,501     13,008     12,047     12,586

  Thursday               12,905     12,489     11,547     12,237     12,295

  Friday      11,780     11,289     10,915     11,197     9,897      11,016

  Saturday    5,699      5,493      5,300      5,538      4,274      5,261
  ----------- ---------- ---------- ---------- ---------- ---------- -------------

Source: Ambassador Bridge

[]{.mark}

From discussions with the Ambassador Bridge, 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 more
frequently and could stretch for several miles along Highway 3.
Ambassador Bridge personnel on the Canadian side also related that
traffic heading for the U.S. picks up around 5:00 A.M. It is busy until
around 9:00 A.M. to 10:00 A.M., then plateaus until around 3:00 P.M.
From 3:00 to 6:00 P.M., traffic falls off.

**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 3-6, the data collection sites could be located at:

-   An advance station located upstream of the commercial vehicle queue
    -- OB-1 and IB-2.

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

The OB-1 collector was positioned about 50 yards upstream from the
tollbooths at a point where all trucks can be seen entering the bridge
(see figure 11). In this position, the collector could see all of the
trucks entering from Porter Street (see figure 12), from the I-96 feeder
road (see figure 13), from Fisher Freeway as they turned sharp right,
and from the duty-free area making a sharp turn on the other side of a
barricade from the main truck traffic (see figure 14). The OB-1
collector did not move out in response to a queue during either
collection period. Had the collector done so, the process is one that
requires care and alertness for safety's sake. In order to stay on the
U.S. side from the Outbound 1 observation site chosen, the collector has
to carefully make his way onto the service road, crossing the flow of
trucks that are making a sharp turn to enter the Ambassador Bridge, in
order to get to the left lane and turn left.

![](media/image12.jpeg){width="4.448611111111111in"
height="1.9694444444444446in"}

**Figure 11. Outbound 1 data collection site just**

**upstream from tollbooths on Detroit side.**

![](media/image13.jpeg){width="4.448611111111111in"
height="1.8430555555555554in"}

**Figure 12. Outbound traffic crossing the**

**Porter Street overpass above I-75.**

![](media/image14.jpeg){width="4.448611111111111in"
height="2.1131944444444444in"}

**Figure 13. Outbound traffic exiting from I-96 feeder**

**road onto Ambassador Bridge, Detroit side.**

![](media/image15.jpeg){width="4.444444444444445in"
height="2.1527777777777777in"}

**Figure 14. Outbound trucks depart main duty free store**

**separated from main traffic and turn right.**

At that point, if moving out to get ahead of a queue the collector must
either: (1) turn left onto Porter Street and left again after crossing
I-75 onto the one-way street (Fisher Freeway southbound) that parallels
I-75; (2) go straight coming out from the bridge and bear left to enter
I-75N; or go straight coming out from the bridge and bear right onto a
service road, after which there is an opportunity to cross over I-75 on
Vernor Street and left again on Fisher Freeway to access the exit ramp
off I-75 southbound. In the vicinity of the bridge, the crossover
streets above I-75 south of Porter Street are Howard Street and West
Grand, and north of Porter street is Vernor.

The OB-2 collector was about 50 yards downstream from primary, next to
the flagpoles beside the Canadian Customs building (see figure 15),
which gave good alignment with the axes of the tollbooths with exiting
trucks. The IB-2 collector was on the left about 50 yards downstream
from primary.

The IB-2 collector was located where the ramp comes up from Wyandotte
Street, across from the duty free area. In this position (see figure
16), the IB-2 collector can record trucks in all lanes of the
directional flow: the mainstream of truck traffic on Huron Church Road
(figure 17), trucks coming up the entrance ramp from Wyandotte Street,
and trucks exiting the commercial vehicle duty free parking area. When
the IB-2 collector had to move out and follow the queue, there was a way
he/she could exit through an adjacent part of the toll facility that is
ordinarily not open except during times of special events or other heavy
traffic. The way out is through a parking lot and left onto Wyandotte
Street W. From there, the collector can cross under the bridge and turn
left to merge onto Huron Church Road southbound, which is the best route
to get upstream to the head of the queue.

![](media/image16.jpeg){width="4.448611111111111in"
height="3.3333333333333335in"}

**Figure 15. Outbound 2 data collector beside Canadian Customs
building.**

![](media/image17.jpeg){width="4.448611111111111in"
height="2.852777777777778in"}

**Figure 16. Inbound 1 data collector at right with**

**Wyandotte Street tollbooths in background.**

![](media/image18.jpeg){width="4.448611111111111in"
height="3.0527777777777776in"}

**Figure 17. Inbound 1 data collection site.**

**Trucks shown just departed Huron Church Road.**

At the Ambassador Bridge, other than an unusual event on the third day,
there was no time at which trucks backed up all the way across the
bridge in either direction. Data collectors in the outbound direction
did not relocate due to an increasing queue length, but the collectors
located in the inbound direction did have to move. Five alternate
locations along Highway 3 (Huron Church Road) were chosen, depending on
the conditions at the time. Any distances given are from the initial
location. Of course, it was easiest to record data at that initial
location close to the tollbooths where trucks move slowly approaching
the bridge to depart Canada.

Two alternate locations were in generally close proximity to the
original location -- walking distance for the collector. The first of
these was 0.15 mile upstream from the original location, where autos and
trucks split as they enter the duty free and tollbooth areas. The second
alternate location was 0.3 mile upstream, where the railroad track
crossed the road beside an intersection with a traffic light.

The third alternate location was 0.65 mile, at the Assumption School at
the intersection of Girardot Street. The fourth was at 0.95 mile, at one
corner of University Mall where Tecumseh road West intersects. The final
alternate location was at a Travelodge motel 2.25 miles upstream, just
before Highway 3 intersects with E.C. Row Expressway (see figures 18 and
19). Of course, all alternate locations were on the same side (the east
side) of Huron Church Road. Even at the intersections, trucks would pass
at highway speeds and would often use both lanes, reducing the number of
vehicles that could be effectively recorded.

![](media/image19.jpeg){width="4.448611111111111in" height="2.0in"}

**Figure 18. Site of farthest Inbound 1 data collection queue site**

**(5^th^ alternate station, approximately 2 miles from regular IB-2
station).**

![](media/image20.jpeg){width="4.448611111111111in"
height="3.3333333333333335in"}

**Figure 19. Inbound 1 data collector at 5th alternate location.**

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 8-10 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 handheld
computers: Palm m100 PDAs for the first collection and Handspring Visor
PDAs for the second collection, both having 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. This method does not factor in delays caused by
traffic lights, however. In the case of the Ambassador Bridge
collection, there were a total of five additional data collection points
that were utilized during the second data collection period, some of
which extended beyond intersections with traffic lights.

**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 general, there were
sufficient records *each day* to meet this requirement.

**Data Collection Equipment**

### 

As outlined in the "Data Collection Procedures" section above, handheld
computers were used as the data entry device and proved adequate to the
task. For the first week of data collection, Palm m100 model handheld
computers were used. It was decided, however, that subsequent data
collection should be done with Handspring Visors. The Handspring Visors
use the same Palm OS (operating system) and have faster processing
speeds (at least in side-by-side comparison with this application) and
larger screen sizes than the m100 models from Palm Computing. 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.

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 20.

![](media/image21.png){width="3.125in" height="3.3125in"}

**Figure 20. 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 Ambassador
Bridge. Hourly volumes are used in the calculation of delay and are
shown with the delay calculations in Tables 8 through 19.

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

  ------------- ------------- ------------- ------------- ------------- ------------- -------------
  **Station**   **5/22/01**   **5/23/01**   **5/24/01**   **6/19/01**   **6/20/01**   **6/21/01**

  OB-1\*        1,126         2,232         1,974         2070          1,842         1,320

  OB-2\*        982           1,287         1,618         2,194         943           2,130

  IB-2\*        1,114         2,049         2,169         2,222         1,965         1,653

  IB-2\*        1418          2,816         2,677         1,720         2,455         1,885

  Total         4,640         8,384         8,438         8,206         7,205         6,988
  ------------- ------------- ------------- ------------- ------------- ------------- -------------

**Table 7. Average Daily Traffic at the Ambassador Bridge**

  --------------- ------------- ------------- ------------- ------------- ------------- -------------
  **Direction**   **5/22/01**   **5/23/01**   **5/24/01**   **6/19/01**   **6/20/01**   **6/21/01**

  Outbound\*      5,923         6,519         6,855         6,328         6,692         6,029

  Inbound\*       5,767         6,441         6,058         6,224         6,316         5,518

  Total           11,690        12,960        12,913        12,552        13,008        11,547
  --------------- ------------- ------------- ------------- ------------- ------------- -------------

##### **\*Note: Outbound means into Canada, Inbound means into the U.S.** 

##### 

##### **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 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. The
number of open inspection booths also affects travel time 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 is 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 tollbooths.

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.

-   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 -- 5/22/2001 -- Outbound

![](media/image22.wmf)

Table 9. Total Delay -- 5/23/2001 -- Outbound

![](media/image23.wmf)

Table 10. Total Delay -- 5/24/2001 -- Outbound

![](media/image24.wmf)

Table 11. Total Delay -- 6/19/2001 -- Outbound

![](media/image25.wmf)

Table 12. Total Delay -- 6/20/2001 -- Outbound

![](media/image26.wmf)

Table 13. Total Delay -- 6/21/2001 -- Outbound

![](media/image27.wmf)

Table 14. Total Delay -- 5/22/2001 -- Inbound

![](media/image28.wmf)

Table 15. Total Delay -- 5/23/2001 -- Inbound

![](media/image29.wmf)

Table 16. Total Delay -- 5/24/2001 -- Inbound

![](media/image30.wmf)

Table 17. Total Delay -- 6/19/2001 -- Inbound

![](media/image31.wmf)

Table 18. Total Delay -- 6/20/2001 -- Inbound

![](media/image32.wmf)

Table 19. Total Delay -- 6/21/2001 -- Inbound

![](media/image33.wmf)

As previously mentioned, the number of open primary Customs inspection
booths was also recorded.

[Weather]{.underline}. The Monday that the data collection team arrived
for the first collection period, a tornado hit Detroit that caused the
police to close certain roads. Since rain was predicted during the
collection period, the team utilized a third rental car, which proved to
be a good decision. During both periods of data collection there was
sporadic rain, generally light. It rained lightly during the first 2
days of 1^st^ collection then it rained hard for a short period on the
3^rd^ day. Rain reduced effectiveness of data collection by about half.
With cars, three collectors were able to record safely and comfortably
during heavy rain. The fourth collector, at OB-2, went into a stairwell
in the Customs building with exterior access and a window where she was
able to continue recording. During the 2^nd^ collection, there was some
rain each day. It rained hard the final day of collection for a two-hour
period, which was the heaviest rain of either collection.

[Unusual Incidents]{.underline}. At approximately 1:30 on June 21, the
third day of the second collection, a dramatic event caused total
shutdown of traffic at this border crossing for a time and delayed
traffic in total for seven hours. Two men were working atop scaffolding
on the U.S. side that was erected for painting a section of one of the
two huge cables that supports the bridge. The scaffolding collapsed and
the men were left dangling from the cable by their safety harnesses high
above the road and the Detroit River. Traffic in both directions was
immediately halted and vehicles on the bridge cleared.

Emergency vehicles and helicopters showed up to assist as necessary.
Colleagues finally pulled the men back onto the catwalk on top of the
giant cable and eventually walked them down carefully. There was total
closure of traffic across the bridge for fifty minutes. Then two lanes
only were open for two hours. Final clearance occurred at 8:30 P.M.
Trucks that had already left the tollbooth were allowed to continue, so
that the trucks that crossed during the emergency registered travel
times that were not significantly different from other hours.

During this emergency, traffic backed up along Highway 3 (Huron Church
Road) as far as the E.C. Row Expressway, 1.9 miles from the tollbooth,
which was the fifth alternate location. The IB-1 collector relocated to
each of the five alternate locations during this time. However, it was
not possible for the OB-1 collector on the other side of the bridge to
safely move out of position and relocate.

On one occasion during each collection (apart from the unusual total
shutdown just mentioned), the supervisor observed exiting traffic (both
autos and trucks) back up on the Detroit side (see figure 21). This
congestion backed up in the right lane of I-75 northbound all the way to
the pedestrian crossover at Ferdinand Street, one mile from the bridge
entrance. Most of this exiting truck traffic continued to turn onto the
bridge, although some turned off to the right prior to the bridge to get
over to Fort Street or other local roads. Also, some trucks were already
on the northbound Fisher Freeway at the point where I-75 exits onto it.
Some of these trucks did not enter the bridge but rather turned onto
I-75, I-96, or local roads. Exiting traffic backed up in the right lane
of I-75 southbound all the way to Tiger Stadium, which is approximately
two miles north of the Ambassador Bridge.

![](media/image34.jpeg){width="4.448611111111111in"
height="2.3631944444444444in"}

Figure 21. Traffic on I-75 northbound approaching Ambassador Bridge
exit.

Detroit rush hour traffic seemed to be the major cause for this backup,
which is unlike the queues encountered at border crossings in more rural
settings. The part of this congestion that is related to the bridge
infrastructure is difficult to separate from the part that is due to the
city road system infrastructure. Traffic did not back up all the way
across the bridge at any time during either collection.

During the first collection, a truck broke down right next to the OB-1
collector in the duty-free truck lane that curves around next to the
OB-1 collector. Bridge operators closed off the affected truck
tollbooth. A tow truck pulled up in front of the OB-1 collector's
location and bridge operators moved plastic barricades (designed to be
filled with water but empty) so that the tow truck backed up to the
stalled truck. Ambassador Bridge personnel then stopped traffic and
moved cones and plastic barricades to allow the tow truck to cross over
from outbound traffic prior to the tollbooth into the inbound traffic
lane heading into U.S. Customs (see figure 22).

![](media/image35.jpeg){width="4.448611111111111in"
height="2.3027777777777776in"}

Figure 22. Tow truck crossing through barricades near duty-free ramp.

## **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 | 5.7       | 8.8      | 13.9     | 4.9      | 55.7      |
+----------+-----------+----------+----------+----------+-----------+
| Inbound  | 12.9      | 20.4     | 33.9     | 13.4     | 65.7      |
+----------+-----------+----------+----------+----------+-----------+

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

Figure 23 illustrates the average travel time experienced for different
truck volumes per lane per hour in each direction.

![](media/image36.wmf)

Figure 23. Average Travel Time for Different Hourly Volumes

Figures 24 and 25 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/image37.wmf)

Figure 24. Typical Inbound Traffic

## 

![](media/image38.wmf)

Figure 25. 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