City of Frisco Engineering Standards

Engineering Standards
D. Minimum Deceleration Lane Storage and Taper Length
1. Deceleration Lane Storage
a. Deceleration lanes are required on Type A and B thoroughfares at all non-residential and
multi-family driveways.
b. All deceleration lane storage areas shall be eleven feet (11’) wide.
c. In locations where there will be less than ten feet (10’) of ROW adjacent to the
deceleration lane, a street easement shall be dedicated such that the combination of ROW
and street easement extends at least ten feet (10’) from the back of curb of the
deceleration lane. Street easements shall extend along the street a minimum of forty feet
(40’) beyond the far edge of the driveway to allow for utility connections.
d. Deceleration lanes will be delineated by using the City’s current Pavement Markings and
Markers standard details.
e. Minimum storage requirements are listed in Table 2.7. Storage requirements may
increase based upon actual and projected traffic demands.
f. A minimum tangent section of thirty feet (30’) shall be provided between the preceding
driveway or cross street curb return and the taper of a deceleration lane.
g. A tangent section is not required when a deceleration lane is immediately downstream
from an intersecting Type A or Type B thoroughfare.
2. Taper Length – The taper specifications for deceleration lane entrance areas are specified in
Table 2.7. The variables used for the specification are shown in Figure 2.17.
TABLE 2.7: Minimum Deceleration Lane Design Requirements
Type of
Thoroughfare
On
Type of
Thoroughfare At
Turn Lane
Width(s)
(ft)
Length of
Full-Width
Storage(ft) (1)
Taper Specifications
Length(ft) R 1 (ft) R 2 (ft)
A
Non-Residential 11 110 (2) 110 (2) 280 280
Driveway
B
Non-Residential
Driveway
11 90 110 (2) 280 280
TxDOT Road Non-Residential
Driveway
See TxDOT’s Roadway Design Guide and Specifications
Frontage Road Non-Residential
Driveway
Apply Type A Thoroughfare specifications to Dallas Pkwy
Apply TxDOT specifications to SH 121 and US 380
1. Measured from the edge of the driveway.
2. When a deceleration lane is immediately downstream from an intersecting Type A or B thoroughfare, its storage
can be reduced to 100 feet and its taper can be reduced to 70 feet (see Figure 2.23)
Section 2 – Thoroughfare Design Requirements May 2012 Page 2-27