Rideau Canal Waterway - Design Criteria for Private Roads


		Design Criteria for Private Roads

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Design Criteria for Private Roads modified by Ken Watson from original notes by Derek Turnbull, Road Superintendent,
Township of Rideau Lakes, 1998

The following is a general guide for private road owners regarding criteria that would ensure that their roads are suitable for emergency vehicle access. With the increased year-round usage of cottages and summer homes, it becomes more critical for private road owners to ensure that your road will allow for access by emergency vehicles. Please note that the driver of an emergency vehicle has the right to refuse to travel a road that is unsafe for that vehicle. It is up to the owner(s) of the private road to make sure that their road can allow safe access of vehicles such as ambulances and fire trucks. The following is a general guideline only, contact your local emergency services supervisors and have them look at the road and make specific recommendations regarding required upgrades.

Minimum Road Widths:

Gate openings should be a minimum of 5 metres (16 feet) in width

tree clearance
Road clearances should be 5 metres (16 feet) between obstructions, preferably 6 metres (20 feet) and 4.3 metres (14 feet) of vertical clearance to allow for clearance of lights and antenna on emergency vehicles.

Passing Lanes: There should be areas where two vehicles can easily pass each other at least every 150 metres (500 feet) or so, with particular attention paid to passing near hills and curves.

Sight Lines: The side of the road and inside corners of curves should be kept brushed out in order to maintain clear lines of sight down the road so that vehicles can see each other, see pedestrians and see passing areas.

curves Curves:

Curves should have a 9 metre (30 foot) internal radius with a 15 metre (50 foot) external radius. This is primarily to allow access to long vehicles such as fire trucks that require a greater turning radius.

Hills:

Hills should have an intermittent slope of no greater than 20% grade (11.2 degree slope). With a proper road bed, this will ensure access in most any condition except severe icing. A sustained grade of no more than 12% is recommended. If the road bed is soft, or there are curves associated with the hill, then a gentler grade may be required.

Ditching is recommended to prevent erosion.

On steeper hills, the application of crushed limestone as a topping provides excellent holding power and erosion control. In some cases asphalting of the surface, particularly near the crown of the hill, will greatly assist vehicle traction and prevent erosion of the roadbed.

Road Bed:

One of the most important aspects is the quality of the road bed. A suggested minimum of 15 cm (6 inches) of granular B (to provide a firm base with good drainage) topped with 10 cm (4 inches) of granular A is recommended. If the road is placed over soft ground, then the thickness of granular B should be increased. Ditching of the road to provide drainage and prevent erosion of the road bed is recommended.

Points to consider are:

the quality of subsurface – is the road traversing outcrop or swamp.
the load capacity of the road during freeze/thaw cycles, particularly in spring.
vehicle traction on curves and hills.
The weight of emergency vehicles such as fire trucks is a great deal more than passenger vehicles – the road design should take this into account.
drainage – is the road creating its own soft spots? Consider using ditches and culverts to prevent the pooling of water at the surface or in the subsurface.