Engineering and Secondary Road Department
County of Linn, Iowa
Directive Number:
SUBJECT: Winter Maintenance Operations
Approval Date:
01/25/2007
Effective Date:
01/25/2007
Revision No.:
6
Reference:
Linn County Snow and Ice Control Ordinance
Policy Section & Number:
SR - 12
Distribution:
Secondary Road Maintenance Crews
Internet
I.
Policy/Purpose
The purpose of this policy is to communicate standard procedure related to winter
maintenance operations, including documentation, evaluation and determinations made
for appropriate response to winter weather conditions affecting the Linn County
Secondary Road System.
II.
Scope
This policy pertains to winter maintenance operations conducted by the Secondary Road
Department on roads within Linn County jurisdiction, responsibility by agreement,
responsibility by general emergency declaration or responsibility by site emergency in
accordance with the Linn County Snow and Ice Control Ordinance.
III.
Objectives
The objectives of this policy are to outline procedures, documentation of road conditions,
factors considered for response, and who will approve and conduct winter maintenance
operations to enhance the use of the Linn County Secondary Road System.
IV.
Definitions
1. Traveled Way: Designated driving surface of a road (including the shoulder).
2. Right-of-Way (ROW): Property obtained through deed or permanent easement
reserved for construction and maintenance of roads (typically 66’ wide on most
county roads).
3. Roadside: Areas within R.O.W. that are outside the Traveled Way.
4. Clear Zone: A distance measured from the outside edge of the shoulder away from
the traveled way (min. 10’) to provide a recovery area for errant vehicles.
5. General Emergency: Is a situation declared by the Governor of Iowa or the Linn
County Board of Supervisors. At such an event the Secondary Road Department
personnel and equipment are directed by the Governor or Board of Supervisors
during declared events.
6. Site Emergency: Is an incident that requires medical, fire department or law
enforcement personnel to render assistance. Traffic crashes involving serious injury,
medical situations, life threatening or fires are examples.
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7. Incident Commander: The emergency response person in charge of the site
emergency.
8. AADT: Average Annual Daily Traffic as surveyed by the Iowa Department of
Transportation (vehicles per day).
V.
Procedure
The Linn County Secondary Road Department does not have a “dry pavement” policy.
We work to improve road surface conditions within the operational parameters
established by existing contracts, agreements and ordinances. During a site emergency,
the incident commander will coordinate requested assistance through the County
Engineer or designee and will direct department activity on site during the emergency.
During a snow event the Linn County Secondary Road Superintendent or designee will
record and evaluate road conditions during normal working hours. This may include wind
speed and direction, air and pavement temperatures, and road surface conditions
(wet/dry) when these parameters are available or measured. The recorded information
may be estimated or observed. Time of day and whether the condition is likely to change
throughout the day may be considered. Personnel involved in responses to winter
weather events and emergencies should document their actions during the events.
Generally, one inch of snow accumulation will trigger a response on priority routes;
however wind conditions may affect type of response and treatment. For example: Wind
may blow the snow off of the road making a response unnecessary when more than one
inch of snow has been reported. Snow with accumulation may trigger action based on
expected weather conditions, such as: dropping temperatures with wet snow or
additional snowfall.
A “graduated response plan” identifies priority routes and is used to provide a limited but
flexible response to winter snow and ice events. The graduated response consists of
specific snow routes run on priority roads during extended hours of operation. During
normal hours, regularly scheduled crews still report to work and plow assigned routes.
Roads with traffic of 1300 AADT or more are designated as primary priority routes and
are plowed/treated first. As possible, the graduated response crew then begins work on
lower volume paved roads listed by the superintendent in the graduated response plan
as secondary priority routes.
Rock surfaced roads will be opened to one lane of traffic and widened to complete
plowing during regular business hours. No weekend plowing is completed unless roads
become impassible. Generally, 5+ inches with blowing and drifting snow will trigger
extended hour activity on rock roads.
Traffic volume varies during the day and should be considered in directing operations.
For example: traffic along commuter routes increases from 7:00am to 9:00am and
3:00pm to 5:00pm with traffic heading to and from work.
Other considerations such as staffing levels, types of equipment available to plow, and
crews and equipment readiness for the next day may also be evaluated and factored
into the decision process.
Winter maintenance operations are completed in accordance with Linn County
Ordinances, Policies and Departmental Procedures in place at the time of the event.
Although the Linn County Snow Ordinance does not provide for replacement of
mailboxes damaged in the course of normal winter operations, the department has
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adopted an assistance program for those who have damage caused directly by county
equipment. The result of a county vehicle crash would be an example. This program
provides a 4X4 post, brace and standard mailbox kit to replace mailboxes damaged or
destroyed by plow impact when the mailbox was in proper location and good condition.
The owner is responsible to install the mailbox.
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