The I-93 ITMS Project
Boston, Massachusetts



This program focuses on I-93 which is the main feeder into
Boston from the north eastern suburbs.



The main problem is that commuters must cross the Charles River
limiting their choices to: I-93, the parallel routes to the other bridges
which cross the river, or the MBTA transit system.

This project seeks to evaluate Intelligent Transportation Systems
(ITS) technology and variable message signage
which can deliver real-time information to the commuters into Boston
while they are on the roadways and highways.
This will include information on:  I-93 congestion,
Park and Ride Lot parking availability for the Orange Line,
alternate route information,
and congestion on bridges across the river and on alternate routes.



To complete this program Mass Highways is utilizing an intelligent traffic
management system with signal control, detection & monitoring capabilities,
and variable message signs displaying traffic information.



Traffic messages will be delivered to variable message signs
placed before critical intersections.
These will warn drivers of bridge congestion and/or
park and ride lot space status.
Drivers will be informed of conditions ahead of them
before they reach an alternate route turn off or before they pass a
park and ride lot with available parking.



The Evaluation Team Consist Of:



    



Study Methodology

A survey questionnaire was developed based on
direction and input from HNTB and Mass Highways.

This survey was designed to specifically address
the potential of the I-93 system to provide useful information
on travel decisions made by end users.
It was also directed at the ability to induce
travel behavior changes in end users,
and evaluate the potential effect
of these changes on the transportation system.
This portion of the evaluation encompasses the before analysis
of user behavior and perceptions towards the information currently available
and what the commuters would prefer to have
in addition to these previous sources of traffic information

A sampling strategy was designed that allowed
for a 95% statistically valid group to be captured from a
roughly conical shaped area of Zip Codes around I-93.

A Map of the Sample Area Showing Yellow Zip Codes
Were Participants Were Reached Who Answered The Survey.

Qualified respondents were randomly selected from
the phone numbers located within these Zip Codes.
There are approximately 903,000 listed telephones in this sample area.
Additionally, a  random digit dialing sample was developed
that provided an equal opportunity to capture
all unlisted numbers within this sample.

Zip Codes within this sample.

This random sample was surveyed using a twenty minute survey with
Computer Assisted Telephone Interviewing [C.A.T.I.] calling techniques.



QA/QC procedures were followed to ensure reliability,
consistency, and accuracy of the interviews.
Interview data was entered into a computer control file
and referenced by unique respondent number.
After interviewing was complete, all files were cleaned, formatted,
and frequency totals were verified to ensure accuracy.
For responses that were open-ended,
i.e., non-structured comments by respondents,
the grouped responses were coded into standard categories of response,
then each individual response was data entered into a special control file.
The data was then re-entered and analyzed according to the
IETP #1 Objectives of the study and the Related Measures of Evaluation.

An Interim Report was presented to HNTB in January of 1999



Baseline Survey Key Findings From The Interim Report:

(From each of the seven objectives outlined in the I-93 Evaluation Test Plan)

OBJECTIVE #1:    Assess the users’ estimate of worth, before, during, and after the test.

• Baseline results indicate that a majority of surveyed motorists currently use a variety
  of available traffic information sources.
• 55% of those surveyed use current sources of information as opposed to
  42% who state they rely on personal experience more than available information sources.
• Radio reports are currently the number one source of information.
  This may indicate a preference for getting on-road, up-to-the-minute information.
• Current information is helpful to the motorists who use I-93.
  However, one in five motorists surveyed state that the information is 'Not particularly useful' or 'Not at all useful'.
• 80% of motorists report current ways that they receive traffic information are working well for their needs.
  About half (47%) of surveyed drivers would like more information than what they are currently receiving
  indicating that the I-93 system should be of great value to these drivers.
• 41% of surveyed motorists report that the current amount of traffic information is ‘About right’.
  14% of those surveyed state they would like to receive 'Much more information',
  and an additional 33% would like 'A little more information'.
• 50% of all users of the I-93 system report that in the past year their travel time on I-93 has increased.
  38% report that it has remained unchanged while 9% report a decrease in travel time.

OBJECTIVE #2:    Assess what information was useful, and what information would be helpful.

• It appears motorists are receiving information that is working well for their needs.
• The main complaints about current information are mainly what the I-93 project should address;
  the information is either inaccurate, not timely enough, not given out frequently enough,
  it doesn't cover enough area or doesn't report adequately on conditions of alternative routes.
• When asked if the current way that they receive traffic information is working well for their current needs,
  80% of surveyed motorists responded affirmatively.
• Reasons that motorists responded negatively include; the information is either inaccurate, not timely enough,
  not given out frequently enough, it doesn't cover enough area or doesn't report adequately
  on conditions of alternative routes.

OBJECTIVE #3:    Assess reliability, accuracy, and timeliness of information received.

• A majority of surveyed motorists feel their current information is at least somewhat reliable and trustworthy.
• Current information was judged to be relatively accurate by most drivers surveyed.
• Timeliness was the most frequently cited problem with current information.
• The I-93 system should provide timely real-time information. Therefore, it should be perceived as reliable
  (trusted as accurate and timely), it should be perceived as accurate (arriving in time to be correct),
  and should be perceived as fulfilling the major desire of surveyed motorists --- timely information to act upon.

OBJECTIVE #4:    Assess perceived change in users’ travel time.

• 71% take I-93 into the greater Boston area at least three times a week.
• 47% of surveyed drivers travel into the greater Boston area via I-93 workdays (Monday-Friday).
• 77% of motorists surveyed report spending 50% or more of their weekly travel on I-93.
• Most motorists felt their travel times have increased or at least stayed the same in the past year.

OBJECTIVE #5:    Assess change in participants’ traveling patterns.

• Motorists seem very familiar with I-93, it's parallel routes, and other alternatives into the greater Boston area.
• 64% of all motorists surveyed report that they use I-93 as their most frequented route into the greater Boston area.
• Route 28 (Magrath-O'Brien Highway) and Rutherford Avenue are each frequented by an additional
  10% of the surveyed motorists.
• The Orange Line is not a first choice of motorists with only 7% of the surveyed drivers reporting
  using the Orange Line as their final means into Boston.
• When asked how many times they had changed their routes due to the current traffic information they received,
  the mean motorist response was 1.6 times a week.
• Overall 67% of all surveyed motorists report changing once or not at all.

OBJECTIVE #6:    Assess motorist perceptions of the effectiveness of the I-93 system.

• Motorists surveyed were perceptive about changes and conditions occurring on highways they frequently drive
  and should be able to adequately perceive future changes that will occur with the implementation of ITMS
  on the I-93 system.
• Most surveyed drivers state that they tend to stay on I-93 or their most frequently used (commute) route.
• When taking an alternate route, motorists wait until they reach the farthest point on I-93
  before taking Route 28, Rutherford Avenue, or parking in an MBTA parking facility.
• The majority of transportation related problems cited by motorists were either construction or congestion related.
  The ITMS should have an impact by informing motorists of these problems, the possible alternate routes
  (and conditions on these routes), or ways to avoid these areas.

OBJECTIVE #7:    Assess the effects of the system on feelings of safety, stress levels, and comfort.

• Stress levels while driving were reported as being fairly high. Two thirds of surveyed motorists
  responded that they were at least 'Somewhat stressed'. 26% reported being 'Very' to 'Extremely' stressed.
• Concern for potential accidents or safety closely mirrors the overall age pattern seen with stress levels.
  73% of motorists report being at least 'Somewhat' concerned about safety or potential accidents.
• As expected increased stress levels and concerns for accidents and safety were related to:
  more frequent travel on the major highways, driving into Boston as opposed to riding the Orange Line,
  and whether you were a younger driver as opposed to an older driver.
• Multiple occupancy drivers (who might also be concerned for the safety of their passengers)
  were more concerned about potential accidents than motorists driving alone.
  

The Final Survey will be administered in 1999
and a final report prepared shortly after survey completion!

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