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M
E M O / N O T E D E S E R V I C E
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M
E M O / N O T E D E S E R V I C E
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To /
Destinataire |
Chair and
Members of Transportation Committee/Président et members du Comité des
transports |
File/N°
de fichier: ACS2006-PWS-TRN-0001-IPD |
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From /
Expéditeur |
Acting Deputy City Manager/Directeur municipal
adjoint intérimaire, Public Works and Services/Services et Travaux
publics |
Contact / personne-ressource : H. Gault 842-3636 ext. 2435 Helen.Gault@ottawa.ca |
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Subject /
Objet |
Impact of
December 16, 2005 Snow Fall Event on Transit Services / Impact de l'incident
de la chute de neige du 16 décembre 2005 sur les services de transport en
commun |
Date: le |
BACKGROUND
On Friday,
December 16, 2005, a snowstorm struck Ottawa with an intense level of precipitation
just at the start and through the morning rush hour. Bus operationsservice, particularly on the Transitway, were was severely affected, resulting in and
many transit customers experiencinged very long delays getting to their
destination.
Staff from Surface Operations, Traffic Operations, Fleet Services, Transit Services and Real Property and Asset Management have reviewed what happened to determine how the negative impact of the storm could have been reduced.
The purpose of this memorandum is to
describe
the impact this storm had on City services and identify ways to improve the
response to future storms to reduce the negative impact on transit. Adocument the verbal presentation was made
to Transportation Committee on January 18, 200618 January 2006.
and iInformation that was
requested at that meeting has been incorporated into this memorandum.
On Friday, December 16, 2005, the
City of Ottawa experienced a very heavysignificant snowstorm that resulted in an
accumulation of 24 centimetres of snow being deposited over a twelve-hour
duration, approximately 11 p.m. through 11:00 a.m. While a storm of this magnitude is in itself
sufficient to cause some disruption, there were aspects of this particular
occurrence which were highly unusual.
Environment Canada has advised that
at 5:00 a.m. on December 16, there were four centimetres of snow down which fell had fallen at a rate of
less than one centimetre per hour.
However, between 5:00 a.m. and 7:00 a.m. another 10 centimetres fell at
a rate of five
5 centimetres
per hour. The remaining 10 centimetres
fell over the next four hours at a rate of approximately 2.5 centimetres per
hour.
The weather forecast was for heavy
snowfall rates in the 2.5 to 3 centimetres per hour range. However, for a two hour period at the start
of the morning rush hour the snowfall rate that was received was five
centimetres per hour or extremely heavy: double what is considered
a heavy snowfall rate and double that which was forecast even that very
morning.
Past experience in managing winter
storms and discussions with Environment Canada staff have defined a snowfall
rate of 2 to 2.5 centimetres per hour as being considered a heavy snowfall rate
so to have 10 centimetres fall within two hours is very unusual. The last severe storm in Ottawa previous to the December 16
storm was in December 2004, when 20 centimetres of snow fell over a
period of 24 hours.
Vehicular Traffic
Traffic
volumes are typically lower on a Friday and due to the advance notice of the approachingforecasted snow storm, some motorists may have adjusted their
travel times to miss the peak hour.
During the snow storm,
traffic conditions were quite variable.
At many major intersections, traffic was waiting numerous traffic signal
cycles to clear the intersection, while at some. On major corridors running parallel to the Queensway, such as
Baseline and Carling, traffic was particularly heavy and further traffic signal
timing changes were made in response to this.
At some major intersections, for example, (Hunt Club westbound at
Woodroffe/Merivale), the queues were often clearing on the cycle
of arrival..
Traffic
Signal Control Systems
The computerized traffic signal system controls and monitors 866 of 1004
signalized intersections in the City of Ottawa. As well, 62 traffic cameras located throughout the City bring
back live video to the Traffic Control Centre.
This allows traffic system operators to monitor live traffic conditions
and make traffic signal timing adjustments as needed to improve traffic flow and minimize delays.
On days when snow conditions are
expected, the signal timing schedule is changed for the majority of traffic
signals on the traffic signal control system.
This may include longer greens or left-turn arrows for critical traffic
movements, as well as expanding the duration that peak hour timing is in
effect. Peak hour timing is implemented
earlier in the day and is maintained beyond a typical end of rush hour. At over 300 locations with newer traffic
control hardware/software and detectors, the “gap time” that is typically used
to decide when to best terminate a green signal is increased in response to the
slower speeds experienced by vehicles approaching the intersection. This will causes the signal to stay green
longer than normal. For example, on major corridors running parallel to the
Queensway, such as Baseline and Carling, traffic was particularly heavy and
traffic signal timing changes were made in response to this.
A
snow storm of this magnitude and duration is bound to be a challenge for
Surface Operations resource capacity to respond while maintaining the service
windows contained within the Council-a Approved Winter Maintenance Quality
Standards:, wherein the
Transitway and highway networks are being the highest
priority, followed by the arterials and then the collector network.
In conjunction with adjustments to signal timing, our Winter Maintenance
Standards have historically proven to be effective in keeping traffic moving safely on the city’s road network. Although routinely aided by Traffic Operations in
the form of adjusted green-light timing on a typical snow
day, aside from the delays to the motoring public and transit users would expect, these Winter
Maintenance Standards have historically proven effective in keeping traffic
moving on the city’s arterial network in a safe manner.
In the case of
the December 16 storm, with the snow forecast to be heavy in and around the
morning rush hour, at the first sign of snow, staff began salting the Transitway and the
arterial roadways. The Transitway and
the arterial network had been completely salted once by 4:00 a.m. Because of the heavy snowfall rate forecast,
staff was instructed to utilize the heaviest salt rate available as the rush
hour traffic would compromise their ability to completely treat arterials a
second time in a timely manner. At 4:00
a.m., a second salting operation was initiated immediately behind the roadway
ploughs. On the Transitway and arterial
streets, roadway ploughs are deployed when a snowfall occurs at such a rate
that the action of road salt does not allow vehicle tires to readily penetrate
the slushy snow to obtain traction. The
Urban Core Roads Division directed maximum resources as per procedure for a
storm of this magnitude, calling in 90 hired and city-owned graders to perform
continuous ploughing in tandem with the city’s 42 salt trucks. Arterials outside the Urban Core area were being
serviced before the morning rush hour by another 81 combination salter/plough
units. However, tThe intensity of the storm caused
traffic bottlenecks in the arterial road network during the morning rush hour, impairing our ability to
continue to clear major corridors of fresh snow.. The major
delays to transit services can be attributed to the roadway inclines located at
eastbound Booth and the Transitway, Slater Street at Bronson, and westbound on
the Transitway at the Bayview Station.
Buses first started to become stuck eastbound at the intersection of
Slater at Bronson with the first bus operator calling at 6:15 a.m. requesting
assistance on the Slater hill. Given
the lower bus and traffic volumes at this time of the morning, significant
delays or back-ups were not experienced.
As the heavy snowfall continued, buses became stuck on the more moderate
grades in the areas of LeBreton Station and Booth Street and on Slater
approaching Bronson. With 450 buses
scheduled to operate approximately every 20 seconds through this key section of
the Transitway during the peak period, beginning at approximately 7 a.m., the
combination of stuck buses and very slow operations resulted in a queue of
buses that extended from LeBreton Station to west of Tunney’s Station. This created customer delays of more than 60
minutes. Bus traffic
gradually began moving as buses were freed from locations that blocked through
traffic. Westbound Transitway service
in the same area was subjected to delays and stop-and-go operation due to stuck
buses in Bayview Station blocking the roadway.
With the snow forecast to be heavy in and around
the morning rush hour, at the first sign of snow staff began salting the
Transitway and the arterial roadways.
The Transitway and the arterial network had been completely salted once
by 4:00 a.m. Because of the heavy
snowfall rate forecast, staff was instructed to utilize the heaviest salt rate
available as the rush hour traffic would compromise their ability to completely
treat arterials a second time in a timely manner. At 4:00 a.m., a second salting operation was initiated
immediately behind the roadway ploughs.
On the Transitway and arterial streets, roadway ploughs are deployed
when a snowfall occurs at such a rate that the action of road salt does not
allow vehicle tires to readily penetrate the slushy snow to obtain
traction. The Urban Core Roads Division
calls in 90 hired and city-owned graders to perform continuous ploughing in
tandem with the city’s 42 salt trucks.
Arterials outside the Urban Core area were being serviced before the
morning rush hour by another 81 combination salter/plough units.
Despite these efforts, and as
could be seen on several traffic cameras located in the areas of the localized
congestion, there were problems experienced by jack-knifed articulated buses
and other buses stuck in the snow that resulted in roadways and major
intersections being blocked for various periods of time.
A side effect of ploughing the
roads clear of snow is the ploughed snow being deposited adjacent to the
curb. Although the travelled lane is now clear, the access to
buses from the bus stops is now blocked.
While trying to get closer to the curb as a
convenience to the transit users, buses would end up straddling the windrow,
which, in the case of this particular storm, was significant. As a result of this practice buses would
become hung-up on the snow bank.
Unfortunately clearing bus stops
during or even immediately after a storm cannot currently be accommodated as
all available resources (city and hired/contract) are still clearing snow from
the transportation network (roads and sidewalks) in order of
their importance as per the Winter Maintenance Quality Standards. Currently the service windows for salting
and ploughing the Transitway is 2 hours followed by arterials which is 3 hours
and major collectors which is 4 hours.
Similarly, the service window for ploughing snow from sidewalks is 4
hours for the downtown business district and 12 hours for all other sidewalks
including bus routes and urban/residentials (although staff have prioritised
sidewalks abutting bus routes and service them within the first 4 hours of this
12 hour service window). . At the
cessation of the storm staff have 10 and 12 hours respectively to plough the
snow from all residential roads and sidewalks.
Then, as per the Winter Maintenance Quality Standards, staff clear snow
from bus stops during the next 12 hours which translates into the fact that all
bus stops are to be cleared 24 hours after the cessation of the storm.
During this storm a routine
survey from field staff indicate that these windows were met.
The most
significant delays to transit developed due to specific problems which, while
major in themselves, also had the complication that they were
interrelated. Immediately west of the
downtown area, buses became stuck on the Gatineau side of the Chaudière Bridge,
causing northbound back up of traffic on Booth Street all the way to Scott
Street and beyond. This traffic caused frequent
blockages of the Transitway/Booth intersection. As well, eastbound buses became stuck at the incline at
Slater/Bronson, which also caused a back-up on the Transitway through the Booth
Street intersection and further west.
Finally, the problems at this intersection were further exacerbated by a
single articulated bus which had problems at the Booth/Transitway intersection
itself. With 450 buses scheduled to
utilize this section of the Transitway during the morning peak, serious congestion developed
quickly. It is also
acknowledged that there were many other specific locations, generally involving
inclines, which transit vehicles were unable to navigate. Bus traffic gradually
began moving as buses were freed from locations that blocked through traffic. Westbound Transitway service in the same
area was subjected to delays and stop-and-go operation due to stuck buses in
Bayview Station blocking the roadway.
In terms of passenger loading/unloading,
difficulties were also experienced as a result of the large windrows left by the ploughing
operations. Although the travelled
lanes were cleared, the access to buses from the bus stops and sidewalks was
seriously restricted. Unfortunately,
clearing bus stops during or even immediately after a major storm cannot
currently be accommodated as all available resources (city and hired/contract)
are still clearing snow from the transportation network (roads and sidewalks)
as per the Winter Maintenance Quality Standards.
On a typical weekday, Transit Operations provides
service to 350,000 daily riders using a peak period demand of 765 buses. Throughout the day, the transit fleet undertakesis assigned to
approximately 1200 daily bus assignmentspull-outs. A review of the transit operations for the weather
event of December 16 indicates bus operators called the Transit
Operations Control Centre 107 times to report that their bus was stuck and that
they needed assistance. Typically for a
significant snow event, Transit Operations would experience 10-12 requests for
assistance from operators with stuck buses
.
The
most severe congestion experienced by transit occurred in the Booth
St/Transitway corridors. Here roadways
or intersections were blocked for extended periods of time (Transitway at Booth
St. and Booth St. at north end of Chaudière Bridge) either by articulated buses
or northbound traffic. The blockage at
the north end of the Chaudière Bridge caused Booth St. northbound to backup
through the Transitway intersection so when the traffic signal turned green for
the Transitway it was blocked by northbound traffic. This severely congested the bus operations along the eastbound
Transitway. Eastbound bus queues did
not clear until approximately 10:30 a.m.
As previously noted,
there were specific bottlenecks which severely affected transit
operations. As well, The Transitway
snow clearing activities
could not immediately address some left several critical areas, resulting unploughed resulting
in numerous stuck buses. The main areas
of concern were the bus loops and roadways leading to the local platform areas
at Blair and Billings Bridge. Similar
problems were encountered at the bus loops and lay-up areas at LeBreton,
Hurdman and Orléans stations. These are
important in that buses finishing their routes must be able to turn around and
wait to start their next run or to enter from or exit to local service at these
locations. The bus-only
off and on ramps east and west bound along the 174 at Montreal Road and Jeanne
d’Arc interchanges were also not cleared of snow in a timely fashionimmediately.
Considerable effort to free stuck buses was made by
staff in many areas. Staff in Transit
Operations worked with Fleet, RPAM, Surface Operations and towing contractors
to free stuck buses. This involved tow
trucks, service trucks, ploughs and sidewalk cleanersclearing equipment. As well, Surface Operations were contacted
to direct ploughing and salting operations to areas with specific problems.Transit
Control did not call Ottawa Police Services during the morning. Although
there are close communications with OPS for accident and incident response, the
stuck buses did not fall into this category.
Surface
Operations were contacted to direct ploughing and salting operations to areas
with specific problems such as Slater at Bronson and various Transitway
Stations - LeBreton, Bayview, Blair and Place d’Orléans.
In response to the
roadway conditions and
blockages, Transit Operations did re-route some cases, Transit service was
detoured buses away
from problematic areas, although this was of limited success as buses became
stuck on the detour routes or were delayed in traffic congestion. Services were detoured in several locations, including: to avoid poor
road conditions and other stuck buses.
These include:
·
Bayshore Station eastbound service in
station detoured to westbound lanes;
·
Data Centre Road to Billing Bridge Station
service detoured to Riverside and Bank ;
·
Brittany Drive service detoured to
Montreal Road and St. Laurent;
·
Blair Station lower level service detoured
to Shopping Centre Road;
·
Place d’Orléans Station service detoured
to Ring Road;
·
Queensway Station upper level eastbound
service detoured to stay on Highway 417.
An example of
the challenges encountered is provided.
In an attempt to ease congestion on the Transitway in the LeBreton
Station area, eastbound buses were detoured through the lay-up area between
Bayview and LeBreton Station. This
detour was abandoned as buses became stuck and blocked the lay-up area forcing
buses to remain on the Transitway.
In addition to the amount and rate
of snowfall, the following factors have been evaluated to determine their
impact on the number of buses stuck on December 16.
An analysis of the location of the
stuck buses shows that Transitway roadways observed the largest percent of
buses stuck at 45 percent. Rideau Street and Gatineau each had seven percent of
the stuck buses. Other roadways
throughout the City of Ottawa accounted for the remainder.
|
Location |
Number of Stuck Buses |
Percent |
|
Transitway |
48 |
45 |
|
Rideau Street |
7 |
6.5 |
|
Gatineau |
7 |
6.5 |
|
Other |
45 |
42 |
|
Total |
107 |
100 |
A closer analysis shows that the
areas most susceptible to stuck buses are as follows:
It is recognized that the statistics do not give an
indication within themselves of the specific impacts to overall operations
caused by individual blockages. An
example is the serious back ups caused by a few buses stuck immediately north of the Chaudiere Bridge.
Over
80 percent of the stuck buses were sixty foot articulated buses. This compares to an on-street fleet of
articulated buses on December 16 of 22 percent. It is clear that these buses were more susceptible to becoming
stuck in the large amount of snow experienced on December 16 than other bus
types.
|
Type |
No.
Buses Stuck |
%
Stuck |
No.
of Pull-outs |
%
of Pull-outs |
|
40’ Low Floor Orion VI |
3 |
3 |
148 |
13 |
|
40’ Low Floor New Flyer Invero |
11 |
10 |
131 |
11 |
|
60’ Low Floor New Flyer D60LF |
88 |
82 |
260 |
22 |
|
Other |
5 |
5 |
628 |
54 |
|
Total |
107 |
100 |
1167 |
100 |
An evaluation of the driving
experience of the bus operators indicates that 37 percent of the bus operators
stuck on December 16 had less than five years of bus-driving experience. This is consistent with the percentage of
operators driving buses on December 16.
|
Years Driving |
No.
of Opts Stuck |
%
of Stuck |
%
of Opts on duty on Dec. 16 |
|
<5 |
40 |
37 |
37 |
|
5 |
20 |
19 |
15 |
|
10 |
8 |
7 |
5 |
|
15 |
8 |
7 |
11 |
|
20 |
14 |
13 |
9 |
|
25 |
12 |
11 |
12 |
|
>30 |
5 |
5 |
11 |
|
Total |
107 |
100 |
100 |
Further analysis of the operators that became stuck
indicates that 13 were stuck twice during their shift and one operator became
stuck three times. A review of the
driving experience for these operators shows that there is no pattern and that
the most senior operator that was stuck more than once had thirty years
experience and the most junior had less than one year experience. Of the 14 operators stuck more than once, 12
were driving articulated buses.
It can therefore be concluded that years of driving experience
was not a significant factor in this event.
Bus Recovery - Towing Operations
The
City owns two large tow trucks, one stationed at 1500 St. Laurent in the east
and the other at the Merivale Garage on Colonnade Road in the west. A towing contract is also in place with J
& E Towing that provides recovery services for the City’s entire fleet of
vehicles. Three of their trucks have
been specially set up to recover buses.
As part of this Standing Offer, two other towing companies are available
to the City once our efforts have been exhausted with the prime contractor
The process for dispatching either
City owned or contracted units is that Transit Services control room staff
contact the Fleet Services supervisor who provided the service using either the
internal resources or contracted resources. However there had been no
pre-positioning or early alerting of resources in anticipation of the eventstorm.
During the eventOn December 16, towing
operations started before 6:00 a.m. and during the day, contractors recovered 31
vehicles, city-towing vehicles recovered 49 and about 37 27 were
able to recover themselves or received assistance from others.
There were three accidents involving buses reported on
the day of the storm and 12 more units were identified after the fact as having
received minor damage. Six buses
sustained such minor damage that they remained in service. The total cost of accident repair incurred
was about $20,500. All buses were back
in service by early January.
The OC Transpo articulated
bus fleet consists of
227 sixty-foot New Flyer low-floor buses (D60LFs) that employ a “pusher”
configuration, with a rear drive axle powered by a rear-mounted engine, with
longitudinal stability of the vehicle maintained by an active hydraulic system
located below floor level at the articulated joint.
This particular design was selected in 2000 for operation in
Ottawa for a number of reasons. The
articulated bus provides increased passenger capacity while the flexible joint
allows safe transit of City streets, in spite of their increased length. Additionally, the pusher type of
configuration generally allows longer length low-floor sections without steps,
while also providing
reduced risk of passenger discomfort due to trace exhaust fumes, high noise and
vibration levels. City transit
maintenance facilities and equipment are also better suited to propulsion
systems that feature rear mounted, upright vertical engines.
The articulated fleet has performed
satisfactorily for five years, and although there have been isolated cases of
unserviceable buses due to winter road conditions, there has been no widespread
events comparable to the number of artics articulated buses immobilized by the December
16, 2005 snow conditions. Pusher
articulated buses also provide satisfactory service in other Canadian
jurisdictions, including Mississauga and Edmonton. As well,
an evaluation undertaken in 2004 by the City of Montreal concluded that the model
used in Ottawa (one of our buses participated in the evaluation) performed on a par with other
articulated configurations in snow conditions.
There are a number of features in
the D60LF design to provide an operating envelope that is satisfactory for the
range of environmental conditions that normally occur in the City:.
1.
A
shorter rear section with a pivot point behind the center axle to effectively
limit the turning corridor and bend angle required.
2.
An
articulated joint design consisting of a ring frame bearing assembly, which
connects the front section to the rear and transmits the loading forces, with a
hydraulically controlled geared section to provide dampening forces to
stabilize the rear section both with the bus travelling on a straight roadway
alignment and with the bus in a bend.
3.
A
programmable electronic controller (on-board computer) to control the degree of
damping that is required at the articulated joint, which is a function of the
bend angle, direction of travel, speed and transmission selection, and is
re-adjusted continuously.
4.
The
actuation of operator warning indicators and control interlocks, if the bend
angle exceeds specific limits; e.g. at 44° bend, before the physical stops are
encountered at 54º, vehicle brakes and throttle interlocks apply and 100
percent dampening is actuated, if in reverse gear.
5.
A joint-override switch to release the
damping and control interlocks for 20-second intervals, if at the maximum bend
angle, which allows the bus to be straightened either by driving the bus if
tire traction is sufficient, or by towing.
6.
Traction
control, which reduced engine torque and uses the Anti-Lock Braking system to
control a slipping tire, under accelerating or launch conditions.
7.
For
deep mud or snow, an override traction control option to allow continuous
rotation of the tires at high throttle.
This feature is intended for travelling short distances over soft
surfaces like snow, mud or gravel, where wheel spin is required to provide
enough drive traction to move the vehicle, and consequently was not effective
in preventing immobilization of many of the articulated buses on December 16.
8.
Relatively
heavily weighted rear and center axles to provide adequate traction with the
buses empty, which is achieved primarily by the rear mounted engine and the
1,100 kg articulation system located near the center axle.
The environmental conditions of December 16 generated extreme road
conditions resulting in a significant accumulation of snow and ice on many City
roadways. A vehicle’s ability to brake,
steer and accelerate is dependent on the tractive force generated at the tire, an ability which is seriously
restricted by snow and ice accumulation., which is directly proportional
to the friction f
actor (or the effective
coefficient of friction) between the road surface and tire, and the normal tire
loading (vertical weight). Average
friction factors of from 0.1 to 0.3 are reported for ice and snow conditions,
as compared to 0.6 to 0.8 for dry pavement, which translates to a loss of traction
under snow and ice conditions ranging from 50 percent to 90 percent.
From a transit perspective,
the impact of the December 16 event storm is best described as
a widespread loss-of-traction event, as it significantly affected most buses in
the fleet. Non-articulated 40-foot
buses became stuck in the snow, as well as a significant number of articulated
buses, at various bend angles, including those that were longitudinally aligned
and yet were still unable to generate sufficient traction at the rear tires to launch move the vehicle.
Intuitively, a pusher articulated bus will have an operational traction
limit in a turn that is less than a non-articulated vehicle, under heavy
snow-load road conditions, as indicated by the high number of articulated buses
adversely affected by the December 16 event.
Increased rolling resistance at the front and centre axles, as well as
any resistive snow loading accumulation under the bus, will tend to decrease
forward momentum of the bus, as tractive forces at the rear drive wheels
generate an increasing pusher force – having a lateral component -- - at the centre axle tires,
as the bend angle increases. If this the lateral pusher forces and the normal centrifugal (or
cornering) force exceed the resistive traction of the centre axle
tires, the centre tires of the bus will skid laterally across the
road surface. Eventually, the added
resistance of the bus being pushed sideways will overcome the tractive force
generated by the drive axle and the bus will become immobilized. As well, under all conditions, the
additional tires resulting from the use of a centre axle on an articulated bus
adds significantly to the rolling resistance, as compared to a 40-foot bus,
which has to be overcome by the rear axle tractive forces.
Tires
All-season tires are currently used on the City transit fleet. These tires range from new to retreads and
incorporate both square and rounded treads.
A measurement survey of the remaining tire tread on the articulated
buses that were immobilized during theon December 16 event showed that tread remaining in all cases
was well within specified ranges.
from 5 mm to 8 mm remaining on the rear drive axle
tires, from 5 to 12 mm on the centre axle tires, and from 8 to 19 mm on the
steering front axle tires. By
comparison, the Fleet administrative minimum is 3 mm for all tires, whereas the
legal limit is 1.6 mm, except for the steering axle tires, which has a 3 mm
limit.
A survey of transit tire suppliers (Bridgestone/Firestone, MichelonMichelin, and Good year)
as well as a survey of other Canadian transit operators (Hamilton, Mississauga,
Kingston, Gatineau, Montreal, and Quebec City) confirmed has revealed that snow
tires are not available for and not used by the transit industry vehicles in Canada. There are all- season tires with different traction
characteristics from those used in Ottawa that may provide improved adherence grip under some winter
conditions. There is no commonly used
pattern or brand used throughout the industry.
A marginal improvement
in drive traction under heavy snow conditions may be attainable through use of tires from a
different manufacturer,
although there also may be trade-offs under other winter conditions such as icewould likely be attainable
through the use of traction tires on the rear
axle of the articulated fleet.
However, traction tires would not necessarily provide improved adhesion
under other winter conditions, such as on ice.
For buses negotiating a turn, it may also be necessary to improve the
lateral resistive traction generated by the centre axle tires This may
necessitate the use of tires with a different tread design at the centre axle.. However, it is very unlikely that the marginalany improvement in adherance adhesion provided by the
use of traction tires would have made a significant difference
given the extreme
road conditions that existed on December 16, a conclusion that is consistent
with results from winter snow tire testing completed by
other transit organizations..
SUMMARY
Surface Operations
At one critical intersection (Booth
and the Transitway) where the roadway incline created a significant problem for
articulated buses, equipment
was redeployed to spread winter grit in addition to the salt applications. the supervisor
for the area redeployed a salt truck to spread winter grit. This remedial action appeared
to give the articulated bus enough traction to navigate the incline
successfully without aid. As a result, should conditions
warrant it, all three, inclines
previously identified in the first
paragraph as trouble spots for articulated transit buses have subsequently and will
continue towill receive de-icing via the regular
salt spreader attending that salt beat as well as an additional
applications of winter
grit to facilitate short-term traction.
As
a second measure, a basic communications protocol has been formalized such that
bus operators and transit supervisors can communicate immediate problems to
Surface Operations staff through the Call Centre. Furthermore, Transit Services and Surface Operations will meet in
the fall to review winter operations procedures and salt beat maps will be
shared.
Operations procedures have also been enhanced as follows:
i)
Bus loop area clearing procedures have been
reviewed and modifications have been implemented to improve the operations;
ii) Bus lanes on Montreal Road and Jeanne d’Arc will be prioritized and will
be done at the same time as Highway 174;
iii) Orléans Station will be completed at the same time as Highway 174.
Bus Operations
On the day of the event, Transit Operations originally contacted Surface
Operations through the City Call Centre.
Direct communications to the various yards responsible for the snow
clearance operations took place after the mid-point of the event. Since this time, direct lines of
communications between Transit Operations Control and Surface Operations have
been established. . The
Transit Control Centre did not call Ottawa Police Services during the morning. Although there is close communications with
OPS for accident and incident response, the stuck buses did not fall into this
category. This issue will be reviewed
to consider how the involvement of the OPS could have assisted with the
response to the problems experienced by the transit service during the storm.
For weekday rush-hour service about 180 articulated buses are scheduled
and these are required for their passenger carrying capacity. However, at off-peak times, when heavy snowstorms are predicted,
it is possible to use standard, instead of articulated, buses on some runs. Off-peak trips tend to
be more discretionary and the number of people using transit in a snowstorm on
a Saturday or Sunday tends to be lower than would be the case in more clement
conditions. Plans are being developed to alter the bus assignments to use more
standard buses in these circumstances. Procedures are already in place to
ensure that there are standard buses available as extras for heavy storm
conditions.
The
way in which the overall incident was managed from the point of view of any
benefits that could have been provided by bringing in Ottawa Police Services
will be reviewed an OPS representative will be included in the Task Force that
has been set up.
Winter driving tips are communicated to bus operators prior to the start
of each winter season. However, discussions with on-street supervisory staff
assisting with stuck buses indicates that the traction control features of the
articulated buses could be better understood by some operating staff. These features as well as a reminder of procedures in winter
storm conditions will be communicated to staff, particularly to those who were
stuck more than once.
Fleet
There are preventative measures with respect to towing operations that
can be taken to minimize the impact of future events of this nature through
closer coordination of event anticipation with Surface Operations.
The feasibility of introducing
program changes to further optimize the degree of hydraulic dampening generated
at the articulated joint under heavy snow conditions is currently under
investigation with the manufacturer of the articulation system.
.Availability
of higher traction tires is being pursued with a trial planned for the winter
of 2006/2007
as directed by Transportation Committee.
Task Force
While the Department
has implemented a number of measures to address issues experienced during the
December 16 storm, it is acknowledged that the magnitude of disruption to the transit users on that day
underscores that a careful review needs to be undertaken to ensure there is no reoccurrence.
Accordingly, aA Task Force has been formed to refine
the improvements already implemented, to ensure optimal coordination and communications
and to develop comprehensive
plans/actions. for
longer-term improvements that have been identified. Membership will include: Surface Operations, Fleet Services, Transit
Services, Traffic and Parking Operations, Infrastructure Services, Real Property and
Asset Management and Ottawa Police Services.
During its meeting of
January 18, 2006, Transportation Committee directed that theThe
Task Force
has been directed to report back to
Transportation Committee inby June 2006.
Original
signed by
R.G. Hewitt
Cc: Mayor and Members of Council
Executive Management Team
Police Chief
A/Director Surface Operations
A/Director Transit Services
A/Director Infrastructure Services
Director Fleet Services
Director Traffic and Parking Operations
Director
Real
Property and Asset Management
Coordinator Transportation Committee
S:\PDAdmin\Gault\Memo\Memo
2006-07\Transp Cttee - Impact of Dec 16 Snow Fall on Transit Services Jan
06.doc