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Chapter 12.53
DRIVEWAYS, ACCESS EASEMENT, PEDESTRIAN FACILITIES, WALKS AND TRAILSSections:
12.53.010 Driveways and access easement.
12.53.020 Pedestrian facilities (urban areas).
12.53.030 Walkways, bikeways and trails.
12.53.040 School access.
12.53.050 Alleys.
12.53.010 Driveways and access easement.
A. General.
1. Driveways and access easements are defined as in DCC Chapter 14.98.
2. Dimensions, slopes and details for all driveway and access easements connecting to a county road shall be as indicated on Figure 4-1 at the end of this chapter. Driveways entering roads with curb and gutter shall meet the requirements of WSDOT Standard Plan F-4.
3. All new or revised driveways and accesses onto a county road (including temporary or construction accesses) require an approved access permit as per the procedures in DCC Title 12.24, “Approaches to County Roads.”
B. Conditions for Approval of New Driveways and Access Easements.
1. Driveways directly providing access onto arterials and collectors shall be denied if alternate access is available. Access onto arterials and collectors may be permitted where no other alternative is available and is approved by the county engineer.
2. Where property has frontage on more than one roadway, driveways and accesses shall be limited to the lowest volume roadway.
3. Driveways and access easements shall have a minimum separation from each other of one hundred feet in rural areas outside of subdivisions.
4. Circular driveways shall have a minimum separation of one hundred feet.
5. In urban areas, driveways and access easements should be located not less than one hundred fifty feet from the nearest intersecting road as measured from the property corner.
6. In areas zoned residential, the minimum separation of individual parcel driveways or accesses, as measured from the centerlines of the driveways or accesses, shall not exceed one-half of the sum of the accessed parcel frontage and each of the adjacent parcel frontages. Joint usage driveways may be required where sufficient spacing is not available.
7. Only one driveway per single residential or commercial unit will be permitted unless the applicant can demonstrate that additional driveways or accesses are needed due to the amount of traffic generated by the project, traffic distribution patterns, impacts to the county road system or public safety and there is sufficient space to accommodate the additional driveway or access. Joint usage driveways are encouraged.
8. All abandoned driveways shall be removed and restored by the applicant or agent.
9. Maintenance of driveways and approaches (and associated culverts where required) onto a county road shall be the responsibility of the applicant.
C. Standards.
1. Common to all driveways and access easements.
a. Clear View Triangle. In addition to providing sufficient sight distances as required in subsection (C)(1)(c) of this section, a clear view triangle as described in DCC Section 12.28.040 shall be maintained for vision safety purposes.
b. Alignment. All driveways and access easements shall intersect the main roadway at an angle between seventy-five and one hundred five degrees, with ninety degrees being preferable.
c. Sight Distance. Sufficient sight distances for vehicles to safely enter onto a public road or street as well as for other vehicles on the road or street to avoid accidents with entering or exiting vehicles is required for all driveways and access points. For all driveways and access easements, stopping sight distance in accordance with the 2001 AASHTO Green Book is required as follows:
To calculate sight distance for existing roads serving a proposed driveway or access, first convert the posted speed to an operating speed as per Table 4-1:
Table 4-1
Posted Speed
Add for Operating Speed
20 mph
0
25 mph
0
30 mph
5 mph
35 mph
8 mph
40 mph
10 mph
45 mph and above
10 mph
Secondly, use the operating speed and determine the minimum stopping sight distances from Table 4-2 (based on an approaching vehicle driver’s eye height of three and one-half feet and an object at the driveway of two feet).
Table 4-2
Operating Speed (mph)
Minimum Stopping Sight Distance (ft.)
20
115
25
155
30
200
35
250
40
305
45
360
50
425
55
495
60
570
The grade of the road can also affect the minimum sight distance required. The following Table 4-3 provides the increase for downgrade and the decrease for upgrade modifiers.
Table 4-3
Increase (ft.) for downgrades
Decrease (ft.) for upgrades
Operating Speed (mph)
3%
6%
9%
3%
6%
9%
20 to 30
10
20
30
—
10
20
31 to 40
20
40
70
10
20
30
41 to 50
30
70
—
20
30
—
51 to 60
50
110
—
30
50
—
Situations with sight distances less than the above must be approved by the county engineer. In these cases, the applicant may also be required to obtain the services of a professional traffic engineer to assess the situation and provide written justification for lesser sight distances.
Sight distances shall be measured from a point ten feet back of the edge of shoulder or back of sidewalk each way along the edge of the traveled way of the main roadway as shown in the figure below.
d. Drainage. Approaches shall be constructed in such a manner as to minimize the runoff from a driveway or other access easement onto the main road.
All approaches at points where there is an existing roadside ditch shall be constructed with a culvert pipe meeting the specifications of the county engineer.
e. Surfacing Within Right-of-Way. That portion of a driveway or access easement connecting to a paved public road that is within the right-of-way of the public road shall be surfaced with a minimum of two and one-half inches of compacted asphalt concrete pavement or equivalent surfacing material to the road.
f. Maintenance. Maintenance of all driveways and access easements including approaches to public roads shall be the responsibility of the owner(s).
2. Driveways and Joint Usage Driveways. Urban or rural driveways and joint usage driveways serving two or fewer lots have no minimum width or surfacing requirements beyond requirements of subsection (C)(1) of this section.
3. Access Easements. Property accesses serving three or more lots and are more than one hundred fifty feet in length as measured from the connecting road near side right-of-way line to the farthest exterior wall of an occupied unit are access easements. Unless an alternate approved emergency vehicle access is provided, access easements shall also serve as an emergency vehicle access. Access easements are privately owned and maintained by the property owners being served and are not the responsibility of the county. Access easements shall have the following requirements and are detailed on Figure 4-3 at the end of this chapter:
a. The minimum width of the tract for the access easement shall be thirty feet.
b. The base and surfacing shall provide a minimum traveled way of twelve feet with turnouts one every three hundred to five hundred feet depending on line of sight, for fifty feet in length and twenty feet in width and be designed and constructed as an all-weather road. A hammer head or cul-de-sac needs to be provided for turn-around. The minimum base and surfacing shall be six inches of compacted gravel base, crushed surfacing base course or crushed surfacing top course. A twenty-foot-wide clear zone will be provided full length for access easement.
c. Suitable drainage in the form of ditches and cross culverts shall be provided along the full length of the access easement. Any bridges or drainage structures shall meet the requirements of DCC Chapter 12.55.
d. The length of an access easement within an urban growth area shall not exceed four hundred fifty feet, excluding the turnaround unless otherwise approved by the county fire marshal, and shall not serve more than three lots. Access easement to more than three lots within an urban growth area shall be via an urban local access county or private road meeting the requirements of this chapter as included in these standards.
e. Access easements outside of an urban growth area shall not serve more than eight lots or parcels. Access easement to more than eight lots outside an urban growth area shall be via a rural local access county or private road meeting the requirements of this chapter as included in these standards.
f. The minimum centerline radius of curvature shall not be less than forty-five feet; provided however, if an approved alternate emergency vehicle access in provided, the minimum centerline radius of curvature shall not be less than thirty feet.
g. The maximum grade shall be ten percent for gravel surfacing and twelve percent for paved portions.
h. The minimum clear vertical distance shall not be less than thirteen feet, six inches.
i. All dead end access easements greater than one hundred fifty feet in length shall be improved with an approved turnaround for emergency vehicles such as a cul-de-sac or hammerhead. See Figure 4-2 at the end of this chapter for acceptable turnaround designs. (Ord. TLS 04-02-30B Exh. A (part))
12.53.020 Pedestrian facilities (urban areas).
Sidewalks are required on both sides of urban streets. See DCC Section 12.52.040(R) for details and exceptions. (Ord. TLS 04-02-30B Exh. A (part))
12.53.030 Walkways, bikeways and trails.
Walkways, bikeways and trails shall be required as identified in the applicable comprehensive plan or separate nonmotorized transportation plan.
Nonmotorized transportation includes travel by bicyclists, pedestrians, and equestrians. Sections 1020 and 1025 of the WSDOT Design Manual will be followed for design of bicycle paths, trails and other nonmotorized transportation. (Ord. TLS 04-02-30B Exh. A (part))
12.53.040 School access.
Sidewalks for school access shall be provided in accordance with the safe walking plans as developed by individual schools and school districts. In addition, walking paths or sidewalks will be required in new plats to facilitate access to schools. (Ord. TLS 04-02-30B Exh. A (part))
12.53.050 Alleys.
Where provided, every alley at the rear of a lot shall have a minimum width of twenty feet. Structural and surfacing requirements shall be the same as the adjoining streets. No dead-end alley or alley with sharp changes in direction shall be permitted. (Ord. TLS 04-02-30B Exh. A (part))
Figure 4-1
Figure 4-2
Figure 4-3
