Our Transportation Monitor

Our Transportation Monitor widget is displayed on our website’s homepage. It is updated daily by 6:15 am with the status of transportation services for that day. The traffic light graphically represents the status of services. A yellow light will be displayed when numerous delays are expected due to poor road conditions or other factors, and a red light will be displayed to notify the community of a cancellation to transportation services.

Current Bus Status
Last Updated: Dec 05, 2023 at 10:24 PM

All transportation is running. There may be some delays.

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Inclement Weather – Cancellations of Transportation

Winter is Coming – Are You Ready for Inclement Weather?

OSTA is responsible for delivering safe, efficient and effective transportation services for the students of the Ottawa Catholic School Board (OCSB) and the Ottawa-Carleton District School Board (OCDSB). OSTA’s decision whether to cancel services or not weighs the degree of risk based on each weather event and its effect on our environment and potential for accidents. Student safety is always our priority.

The Ottawa Region is nestled in a valley, creating unique weather patterns. For example, one region could be in the midst of a winter storm, and Ottawa could be in the sunshine. We base our decisions on the most up-to-date information we have for the area OSTA serves.

OSTA’s transportation system serves urban, suburban and rural communities. We also recognize weather conditions can vary from community to community.

Cancelled Services

OSTA’s decision to cancel services must take into account the forecasted weather for the entire school day. Whether the risk is too high during morning service or anticipated to be too high during the afternoon service, a decision is made by 5:30 a.m.

OC Transpo, however, continues to operate, and students may use public transit to get to their school. Schools remain open, and students will be welcomed, as usual. Ottawa Safety Council determines service cancellations for OSTA’s Walking School Bus routes.


Parents’/Guardians’ Decision

Parents and guardians have the choice of whether to access OSTA’s transportation services during a weather event, or whether to keep their children at home. Conversely, parents and guardians may also choose to take their children to school when transportation services are cancelled. If they do so, they must also make arrangements to pick their children up at the end of the school day.


No Zone Cancellations

OSTA’s system is vast and comprises different communities. Drivers and students often travel across the City from rural to urban areas, and vice versa. To further complicate matters, sometimes the poor weather marginally affects one area, and is dangerous in another.

Cancelling zones of the system is not an option. Some students travel through different zones to get to school. Cancelling designated zones would be confusing and dangerous. Consequently, OSTA’s service cancellation is for our entire geographic service area.

For the most part, OSTA tries to align its service cancellations with its neighbouring consortia. Our rural areas are connected and potentially experience similar weather effects. There are occasions, however, when OSTA may opt for a different decision than its neighbours. If OSTA continues to provide service, while others cancel, OSTA will confirm that services for OCDSB and OCSB are still running through its communication protocols.


Communication Channels

There are many ways parents/guardians and students may get information regarding OSTA’s service cancellations:



Daily – OSTA reviews forecast reports from various accredited sources. If a weather event is expected, which may significantly impact safety, OSTA proceeds to further steps.

4:00 a.m. – 5:30 a.m. – OSTA reviews forecast and examines current weather patterns from various sources, including weather radars. OSTA communicates with neighbouring consortia and other transportation partners to get their input on conditions in their area. OSTA may also conduct a road test.

5:30 a.m. – OSTA decides whether or not to cancel transportation. If the decision is made to cancel services, OSTA begins its communication protocol:

  • Operators are contacted to start their communication with drivers
  • Media outlets are contacted by phone to announce the decision to the public over radio, TV and online
  • Messaging to Parent Web Portal email subscribers, Twitter and Facebook
  • Posted message on OSTA website and the traffic light icon turns red
  • Messaging to school boards for further distribution through their channels

6:15 a.m. – OSTA communication protocol is complete.


Weather Conditions to Consider

There are many conditions, in combination, which increase risk. There is no absolute determinant for service cancellations. Conditions are evaluated as a whole to determine risk:


Type of Precipitation 

  • Snow – Flurries, large wet flakes, granular, mix
  • Rain – Rain, freezing rain, ice pellets, mix
  • Rain/Snow Mix


Amount and Rate of Precipitation

    • Hourly amounts which may exceed the City’s ability or warrants to clear necessary roadways during core service hours, and or affect visibility
    • Total accumulation which may exceed the City’s ability or warrants to plow vital roads during core service hours


Other Factors

  •  Air/Road temperature and dew point affects the degree to which snow/freezing rain will fall, stick or melt while falling and or once it is on the road surface
  •  Wind speeds/wind gusts affect bus/van stability on icy surfaces, visibility related to the rate of precipitation and or blowing in open spaces
  •  The condition of roads at the time of weather events such as bare pavement, patchy ice, glare ice, icy ruts, packed snow, loose accumulation, slushy, slick and combinations.
  • The visibility such as the line of sight to distance, visibility of roadway, blowing snow coming down or across sightline, snow drifts, etc.
  • Probability of precipitation may be low, mid-range or high, combined with expected accumulation (low, medium, high volumes) determines likelihood of anticipated weather effect actually occurring at the estimated times
  • Radar models showing consistent path across region or potential re-direction


No Temperature Thresholds

Throughout the winter, temperatures may dip as low as -25C to -35C plus wind chill. Ottawa Public Health provides “frostbite warning” or a “frostbite advisory”. Parents must always take the appropriate precautions to dress their children warmly, preferably in layered clothing, coat and snow pants with hat and mittens or gloves and a face cover where necessary. They must also stay with their children at the bus stop.

OSTA does not have a temperature threshold at which it will cancel services, except if the equipment is adversely affected and buses cannot start in the extreme cold. That would generally require an ambient temperature (no wind chill) of -40C or lower, which is highly unusual in the Ottawa Region.

OSTA did review the possibility of adding a temperature threshold to its evaluation in February 2019. It was determined this would result in frequent service cancellations due to the high number of days with these low temperatures.


Year Weather Assessments Cancellations Frostbite Warning
-35 windchill
Frostbite Advisory
-25 windchill
2018-19 (as of Feb 22) 29 7 1 9
2017-18 19 4 2 8
2016-17 27 5 1 11
2015-16 14 5 n/a n/a
2014-15 9 1 5 19
2013-14 12 3 6 15
2012-13 n/a 6 2 2
2011-12 n/a 3 0 5
2010-11 n/a 3 1 9


  • n/a, data not available


To Cancel or Not to Cancel

The final decision to cancel buses or not is complicated. It depends on a myriad of factors, and those factors can change within minutes. Below are some examples.

  • Small amounts of freezing rain falling from 5 a.m. to 8 a.m. on bare pavement, anticipated accumulation 1mm, road temperature -3C with no prior salt treatment, road test at 5 a.m. does not yet demonstrate slippery surface, but some precipitation is freezing on contact and likely to stick throughout morning service, probability of precipitation mid-range to high (75%) = CANCEL
  • Snow flurries to start at 2 a.m., rate of precipitation 0.2cm/hr over 10 hours for a total accumulation 3-5cm, the road surface has packed snow on roads recently cleared from previous snow event, wind at 20km/hr, road test on suburban/rural roadways slow but manageable, probability of precipitation low (30%) = SERVICE
  • As of 4 a.m. reports, clear morning expected but snowstorm forecasted to start at noon, wind gusts expected to be 40-50km/hr, rate of precipitation expected 2-3cm/hr, accumulation by the start of service at 2 p.m. anticipated to be 7cm or more, low visibility expected, probability of precipitation high (90%) = CANCEL
  • Reports show snow flurries changing to mix rain/freezing rain forecasted to begin at 2 p.m. and end at 6 p.m., road temperature -1C, snow 3cm total accumulation on the roadway before 2mm rain/freezing rain (loose snow absorbs rain), probability of precipitation mid-range (40%) = SERVICE
  • Wet snow starting at 5 p.m. until 5 a.m. the following morning, current road surface icy ruts for the past week or more. The total accumulation anticipated is 13-15cm with expected rate of precipitation is 1.5cm/hr during the event. Observe that no snow is falling as of 4 a.m., total accumulation was only 10cm at time of assessment, snow clearing on major/minor collectors is underway, road test demonstrates packed snow on some roads where cleared, some icy spots where snow was scraped and loose snow in some more remote areas, probability of precipitation low (10%) = SERVICE.

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