Loading...
Magnolia North-SY130321 0 Binkley w ; I CO consulting engineers March 21, 2013 TTC Attn: Tommy Tabor, P.E. 1301 East Debbie Lane Suite 102 — 152 Mansfield, Texas 76063 RE: Addendum to the Traffic Impact Analysis Magnolia North Addition Tommy: At your request we have prepared this addendum to the TIA that was prepared on March 15 for the Magnolia North Addition site in Coppell. The purpose of this addendum is to summarize the Impact on Natches and Waverly section of the TIA report. The following paragraphs were prepared accordingly. SUMMARY OF THE IMPACT ON NATCHES AND WAVERLY IMPACT BASED ON PROPOSED RESIDENTIAL ZONING If the proposed site were to be developed as single family residential, the traffic on Natches would increase from 127 vehicles to 132 vehicles in the morning peak hour — an increase of 5 vehicles or 4%. It would increase from 138 vehicles to 154 vehicles in the afternoon peak hour— an increase of 16 vehicles or 12%. The traffic on Waverly would increase from 35 vehicles to 40 vehicles in the morning peak hour — an increase of 5 vehicles or 14%. It would increase from 35 vehicles to 51 vehicles in the afternoon peak hour— an increase of 16 vehicles or 46%. IMPACT BASED ON EXISTING RETAIL ZONING If the proposed site were to be developed as retail, the traffic on Natches would increase from 127 vehicles to 161 vehicles in the morning peak hour— an increase of 34 vehicles or 27%. It would increase from 138 vehicles to 236 vehicles in the afternoon peak hour— an increase of 98 vehicles or 71%. Binkley&Barfield-C&P,Inc. • TBPE F-3815 • 1801 Gateway Boulevard,Suite 101-Richardson,Texas 75080 • Tel:972.6442800 I Fax:972.644.2817 www.bbcpi.com The traffic on Waverly would increase from 35 vehicles to 69 vehicles in the morning peak hour — an increase of 34 vehicles or 97%. It would increase from 35 vehicles to 133 vehicles in the afternoon peak hour—an increase of 98 vehicles or 280%. CONCLUSION The traffic increase assuming residential zoning ranges from a low of 4% to a high of 46%. Assuming retail zoning the traffic increase ranges from a low of 27% to a high of 280%. The proposed residential zoning will produce significantly less traffic than does the existing retail zoning. CLOSING We appreciate this opportunity to respond to your need for traffic engineering assistance regarding this project in Coppell. If you have any questions concerning this document, please do not hesitate to contact our office. Sincerely, Binkley & Barfield I C&P, Inc. Dannie R. Cummings, Principal Engineer TRAFFIC IMPACT STUDY FOR THE MAGNOLIA NORTH ADDITION Prepared for TIMBERLAND CREEK COMPANIES, INC. March 15, 2013 .t�OF O tt col. „ ..; DANNIE CUMM . rl f 60347 ,i ‘‘ j r m " r cmuno- { 0 kS By Binkley & Barfield 1 C&P Consulting Engineers Dannie Cummings, P.E. 1801 Gateway Blvd. •Suite 101• Richardson,Texas 75080• (972)644-2800•Texas Registration No.F-3185 TRAFFIC IMPACT STUDY MAGNOLIA NORTH ADDITION CITY OF COPPELL DEVELOPMENT SITE This report addresses the development of a proposed 5.14 acre site located in the southwest quadrant the SH-121 and Denton Tap Road interchange in the City of Coppell. The property is proposed to be developed as a singly-family residential site with 28 homes. The Magnolia North Addition site will provide only two driveways or access points to serve residents seeking to enter or exit the site. These two driveways are proposed for the SH- 121 eastbound frontage road and are planned to include right-turn deceleration lanes at both driveways. No other driveways or access points will be provided to serve the site. A location map from the NCTCOG web site has been included as Figure 1 on the next page of this report. A copy of the site plan and an aerial photograph of the area has been included in the Appendix of this report. PURPOSE OF STUDY The purpose of conducting this study was to address three specific areas of concern as listed below. The access connection spacing along the SH-121 eastbound frontage road. The taper and storage requirements for the two right-turn deceleration lanes proposed to be constructed on the SH-121 eastbound frontage road to serve this site. Should acceleration lanes be considered for the two site driveways on the SH-121 eastbound frontage road? Page 1 ICopyright NCTCOG 3040 RoUnd tF d E fm3Q4 . r I t Round Ia ,K , Branch w F } -C3 It Nfall Dr Spirks Rai ❑ s ` I ..sv,,,,,,r, ,.,:,:;:,,,,,,,.„::,,,,c‘:;,.,,, ,,_,,,.,$A3f.„.,,, c \and DI - y-Tod T I � � SITE' �- - ° - r Jr I Cdr " - r it : East ti, t-park ' .- a � C --, c,i,`, rkdw E -PaTkt y'of 1 I r 7 d Like Rd 1 � Z I CkM - r I u.5 km I0.51 mi i. z. of IPark 0 r A i'L.._ �' '. Ce �® DISCLAIMER t This data has been compiled for I t, NCTCOG. i LOCATION MAP Various official and unofficial �� sources were used to gather this DFWMaS.corn information.Every effort was made p to ensure the accuracy of this I °HIV -�- data,however,no guarantee is +I rth Cefaar !7cx given or implied as to the accuracy of said data. 1. C{+unci of Ccek::-rnorrlettrits FIGURE 1 ACCESS CONNECTION SPACING The TxDOT Access Management Manual(AMM) identifies the required spacing criteria for streets and driveways that intersect the state highway system. Table 2-1 of the manual indicates a minimum connection spacing of 425' for one-way frontage roads with posted speed limits that equal or exceed 50 mph (the posted speed limit on the frontage road is 55 mph). The access connection spacings along the frontage road are summarized in the following Table 1. TABLE 1 Access Connection Spacings SH-121 Eastbound Frontage Road ACCESS CONNECTIONS 1 SPACING Denton Tap Road to the ViewPoint Bank Driveway Approximately 160' ViewPoint Bank Driveway to the Proposed East Site Driveway Approximately 432' Proposed East Site Driveway to the Proposed West Site Driveway Approximately 322' Proposed West Site Driveway to the First Driveway West (a One-Way Outbound Driveway) Approximately 368' The table above also includes the first access spacing on the frontage road west of Denton Tap Road. As can be seen in the table the existing bank driveway's spacing to Denton Tap Road is 160' and therefore does not comply with TxDOT's access spacing criteria. Our review of these measurements indicates that two of the three site applicable spacings will not comply with TxDOT's access connection spacing criteria:the 322'spacing between the site's proposed west and east driveways; and the 368' spacing between the site's proposed west driveway and the first access point west of that driveway. The spacing that does comply is the 432' spacing between the ViewPoint Bank driveway and the site's proposed east driveway. Page 3 A variance to TxDOT's access connection spacing criteria is required in situations where the spacing criteria is not satisfied. Four key considerations create a favorable environment for the approval of such a variance for the two site spacings that fail to comply with the spacing criteria. A minimum of two access points to subdivisions are typically required by Cities as a safety measure to insure adequate access by police, fire department, and other emergency vehicles. Both driveways will be constructed with right-turn deceleration lanes. These turn lanes will help to reduce the impact to through traffic flow by removing right-turning vehicles from the through traffic lanes. The existing access drive west of the site's proposed west driveway is a minor driveway 16' in width that allows only one-way exiting traffic onto the frontage road. The traffic volumes entering and exiting this site are very small. As seen in Table 2 the morning and afternoon peak hour periods are expected to generate only 29 vehicles and 33 vehicles respectively. TAPER AND STORAGE REQUIREMENTS The design guidelines for the two right-turn lanes on the SH-121 eastbound frontage road have been summarized in the following Table 2. These guidelines are based on Table 3-3 of TxDOT's Roadway Design Manual. TABLE 2 TxDOT Turn Lane Design Guidelines DECELERATION STORAGE TOTAL LENGTH * LENGTH LENGTH 510' 100' 610' * Deceleration length includes a taper length of 100'. Page 4 A review of the available frontage along the frontage road between the one-way access drive and the beginning of the existing right-turn lane that serves the ViewPoint Bank indicates that there is room to construct only one 610' right-turn lane. This one right-turn lane would serve the east site driveway, but it's construction would also require that the west site driveway be constructed within the deceleration portion of the overall right-turn lane serving the east driveway. This may be acceptable to TxDOT. However we would suggest that the Owner request Txdot approve the construction of two right-turn lanes as shown on the site plan and that they be constructed to the same deceleration and storage lengths as was used in the construction of the right-turn lane serving the ViewPoint Bank. Those approximate dimensions are listed in the following Table 3. TABLE 3 Existing Right-Turn Lane Dimensions DECELERATION STORAGE TOTAL LENGTH * LENGTH LENGTH 200' 75' 275' * Deceleration length includes a taper length of 100'. ACCELERATION LANES We do not recommend the use of acceleration lanes to serve the site traffic exiting onto the frontage road from the two site driveways. The distance needed to construct acceleration lanes for the 55 mph speed limit along the frontage road is not available. Also, the nearby traffic signal at Denton Tap Road will create stop conditions due the red signal that will significantly reduce the effectiveness as well as the need for acceleration lanes. CLOSING We have appreciated the opportunity to assist you in the preparation of a traffic impact study for the Magnolia North Addition site in Coppell. Please do not hesitate to contact our office should you have any questions or comments concerning this report. Page 5 APPENDIX Site Plan 1 Page Site Aerial 1 Page Page 6 I i I JJ rvIPH waor sula: ss-x seat law a wax I war srwaw r�caae-x•mac aoaewwxaoae \ oue w ewc a asa S I .G a_ J '--, ,-[vi tzcnva '7 :'r" / r. - .. . m ..I' �x n ro�wr ' i p>�x.,,. f!�a+z'prr+_S4. dnr ,�. •,,..:. ...: ups __ .. 1! ttI tx. i - ' n �. r .. •.. .sr+.INNIM'aIIIII s.c..��w.. X ^fit —is i z::zz a i c �•-^ _ 'sic ., „ _ r L ,r , 11 [-. } _ 5 t1-j ' ` f "Tr •4 p +t•. try d � - - �,�' % ;v 3' l':.,',7-1 ';:i,' _Y; I F yn*�k ? - ' - 1�"1 ..-. 4 t 1,.,"1..:y i`;i ' M* x.nS,t - - "� t ,',•t-1:1',,i. ,'A`54 Ck �. , {.,'��� ca _,-pY . f 1 , . ...-.3 a., �.i..,k; , ... . ., i' ., "l 'r r .sw ' 'I': 'v a.' �'` , - #,, 4 ,-„_, few . , y cox ar -fir...., . r'. ,a _ r�. i n:-v 4 s 0 p l � to .,r, /* -r}e 44 j I +kr i-%�- �` } --'� _ - •e fs - r rra rr ` ya4 r 3 - -- 1 . Y_...1...-.:j2-11-. — ' -is. 5.. y S <t ,• am..,.. :" :..r: ' H t r " , %a • - . . 44 gg a x . -'oir- q . r •.. .•'• :x'yright NC G r'w.> ., ... � -, ,:.:-.4,,, , ;.4.-,,,,i •,.....atO,::;....i;::?j;:::,.TriVII,g, ''''''..1 '; -' ‘:-.' . ' ' 1.-:;.1:1; .' - 1 --7:'E: ":4_r-r.,7:77,,,-,,::____:i.1.1 .1.,-,,,,-.: 44..,,,,, -...''',-4'ff`*•--,-,,,,„,, ; ', �i. iV r x , j-^t. ' ;„,...4C r . : .ms :: '�.� - rt �. ip. ,.� � :r, f� e ; .. __ 1 I 4 714 i .....r''. yi `' f ',k',� ••` 7 - . '`vim: "'V" dI - c •_ x.,y . ,,, .. . . `.‹...;' .r r.^� '• w, 4 ?- ) + — ,# josr d ' b"r ' TI �0.`.bd f . .,r s. Wit, Yri ',` +r •.A ;kt� , `. • 11 ^ pr, , ',. . . ^ ': ,, _ t = f 300{ : ` /.• DISCLAIMER This data has been compiled for N I SITE AERIAL NCTCOG. i Various official and unofficial sources were used to gather this DFWMaps.com information.Every effort was made i I to ensure the accuracy of this data,however,no guarantee is North C+�•nir.41 �C given or implied as to the accuracy Council of P','r mores of said data.