Chapter 8.qxd

Chapter 8 8.1

Overview and VisionMost residents, employees and business

owners who contend with movement throughthe community on a daily basis experienceincreased traffic congestion and frustratingtravel delays. This Comprehensive Planextends the City’s street system to accommo-date future traffic and creates opportunitiesfor non-automotive transportation by masstransit routes, a system of bicycle and pedes-trian trails, and supportive development pat-terns with jobs and housing in close proximi-ty. Following this Plan, the City participatesin regional efforts to manage transportationdemands and to design a more balanced com-munity to reduce the current reliance on auto-mobiles.

This chapter identifies the transportation

challenges facing Thornton, establishes aphased program of roadway improvements tomeet future traffic demands and recommendsfuture transit and trail routes. Since there isan extensive discussion of future improve-ments in this chapter, a separateTransportation Master Plan is unnecessary.

Key ChallengesMaintaining Adequate Levels of Services

The City faces increasing demands on allits streets, particularly 104th and 120thAvenues – the key access points to I-25. TheCity has limited ability to unilaterallyincrease capacities along roadways, so it mustpursue improvements that require participa-tion of other entities.

...identifies key

transportation

challenges and plans

for future

transportation

system

improvements to

meet projected

demands.

Chapter 8

Transportation and TransitThornton’s transportation system should provide access for all residents. While existing

land use patterns and practices suggest that residents will continue to rely on the automobile tomove throughout the community and region, alternatives to automobile travel are an importantpart of the Plan. Land use patterns, employment opportunities, household characteristics,resource availability and other factors determine future transportation system demands. Asidentified in the Vision, Thornton’s transportation system in the year 2020 functions “...safelywithin neighborhoods and efficiently to and from work, schools, shopping and other destina-tions.”

Traffic congestion during the morning rush hour on southbound I-25 can be very frustrating for Thornton residents.

Timing Roadway Capacity with NewDemands

A key element of main-taining adequate levels ofservice along communityroadways is to coordinatedevelopment approvalswith available street capac-ity. This may mean thatthe City delays somedevelopment until ade-quate capacity is availableor arrangements are madeto fund improvements pro-viding adequate capacityconcurrently with newdemands.

Remedying Existing DeficienciesIn addition to interstate interchanges,

Thornton needs better connections within thecommunity and to adjacent communities.Improved traffic flow to the south and east, aswell as the connection of Thornton Parkwayto Colorado Boulevard reduces the City’sreliance on the I-25 interchanges at 84th,104th and 120th Avenues. The Plan alsoreduces demands on the City’s crowded east-west corridors (88th, 104th and 120thAvenues).

Coordinating TransportationSystem Improvements with OtherEntities

The planning and development of newinterchanges along I-25, I-76 and the pro-posed E-470 requires the participation of the

Denver Regional Council of Governments(DRCOG), the Colorado Department ofTransportation (CDOT) and adjacent munici-palities.

Developing Effective Alternativesto Single Occupancy Vehicles(SOVs)

The popularity of the automobile relates toperceived low costs as well as convenience,speed and flexibility in moving peoplethrough the community. However, as envi-ronmental concerns and the costs of manag-ing congestion increase, providing alterna-tives to SOVs becomes a growing concern. Acombination of strategies, including masstransit, better transportation system manage-ment, transportation demand management,and bicycle/pedestrian trails may help reduceour reliance on SOVs.

EnsuringAccess for AllResidentsLower incomehouseholds, theelderly, the handi-capped and theyoung have accessneeds that cannot bemet by automobiles.These populationsrely more heavily onmass transit andtrail options.Increasing numbersof senior citizens

City of Thornton Comprehensive Plan8.2

Exhibit 8.1: RoadwayFunctionalClassifications

Exhibit 8.1: Roadway Functional Classifications

Type ThroughLanes

Typical CharacteristicsTraffic Control Daily Volumes Examples

Regional Arterials (Freeways) 4 to 8 Grade SeparatedInterchanges 50,000 to 200,000 I-25

E-470

Major Arterials 4 to 6 Signals 15,000 to 50,000 104th Ave.Colorado Blvd.

Minor Arterials 2 to 4 Signals 5,000 to 20,000 128th Ave.Holly St.

Major Collectors 2 to 4 Signals or Stop Signs 2,000 to 10,000 Riverdale Dr.Grant St.

Minor Collectors 2 Stop Signs <5,000 Corona St.Pearl St.

Residential (Local) 2 Stop Signs <2,000 High St.99th Ave.

The transporta-tion system isone of the most visiblemeasures of theCity’s quality of life.

Providing an alternative to single-occupant vehicles is becoming a moreurgent issue as traffic congestion and environmental concerns increase.

Chapter 8 8.3

and youths without an available parent toprovide transportation (due to a rise in dualincome and single parent families) exacerbatethe problem. When planning for additionalcapacity, the City must consider these specialneeds populations.

Existing RoadwaySystemRoadway Characteristics

Roadways in Thornton are assigned one ofsix functional classifications based on suchfactors as function, travel speed, frequencyand type of access, continuity, and traffic vol-ume. Exhibit 8.1 defines the characteristicsof each of these roadway classifications.

Exhibit 8.2 (next page) shows the road-ways representing the four highest levels inThornton’s functional classification system,including regional arterials, major arterials,minor arterials, and major collectors. Thereis an extensive network of minor collectorand local streets not shown. The exhibit alsoincludes the number of through lanes on eachroadway segment and indicates unpavedroads.

I-25 is the only regional arterial in the City,serving as the major north-south regionalroute. Access to I-25 islimited to 84th Avenue,Thornton Parkway,104th Avenue, 120thAvenue, and StateHighway 7. The dis-tance between the inter-changes at 120thAvenue and StateHighway 7 is six miles.

Thornton has a basicone-mile grid of east-west and north-southarterial streets typical ofDenver and other mid-western and westernmetropolitan areas. However, there are sev-eral interruptions in this arterial grid in andaround Thornton. In the east-west direction,most arterial streets are not continuous acrossthe entire Planned Growth Area. Only 104thAvenue and State Highway 7 provide contin-uous access across both I-25 to the west andthe South Platte River to the east. Gaps with-in Thornton exist in other east-west arterialcorridors, including Thornton Parkway, 112th

Avenue, 136th Avenue, 144th Avenue, and152nd Avenue. 120th Avenue continuesacross Thornton but does not presently crossthe South Platte River.

In the north-south direction, I-25, HuronStreet, Washington Street, and ColoradoBoulevard are the only continuous arterialstreets through the Thornton Planned GrowthArea. Washington Street provides access toDenver, while Colorado Boulevard terminatesat 88th Avenue and Huron Street terminatesas a major arterial at 84th Avenue. Gapsexist in the other north-south arterial corri-dors, including York Street, Holly Street,Quebec Street, and Yosemite Street.

Arterial streets in the more establishedparts of the City, generally south and westfrom 136th Avenue/Colorado, are in manycases developed as four to six lane streets.Roadways in the less developed parts of theCity are generally two-lane rural type roads,in many cases unpaved.

Traffic VolumesThornton has three different ranges of traf-

fic volumes on arterial and collector streets.I-25 exhibits the highest volumes, rangingfrom 50,000 to more than 100,000 vehiclesper day. Volumes in the 25,000 to 50,000range are observed on portions of 84thAvenue, Thornton Parkway, 104th Avenue,

and 120th Avenue near I-25 interchanges, aswell as southern portions of WashingtonStreet. Other arterial and collector streetsgenerally have daily traffic volumes of20,000 or less.

Capacity and Congestion Typical capacities for various roadway

types and configurations for reference pur-poses are listed on Exhibit 8.3.

Exhibit 8.3:

Typical CapacityThresholds by

FunctionalClassification

(Vehicles per Day)

Exhibit 8.3: Typical Capacity Thresholds by Functional Classification(Vehicles per Day)

Functional Classification Maximum Daily Traffic Volumes For:

2 Lanes 4 Lanes 6 Lanes 8 Lanes

Regional Arterial - 80,000 120,000 160,000

Major Arterial 16,000 32,000 48,000 -

Minor Arterial 12,000 24,000 36,000 -

Collector 10,000 20,000 - -


Chapter 8 8.5

The most congested streets in Thornton arecurrently 104th Avenue and 120th Avenue. On104th Avenue, the street segments on whichvolume exceeds capacity include the four-lanesegments west of Colorado Boulevard andwest of Huron Street, and the two-lane seg-ment east of Colorado Boulevard extendingeast of Thornton. This situation shows thatthe capacity of 104th Avenue has not keptpace with the demands placed on this corridor.The situation is significant because 104thAvenue is not only a major transportation cor-ridor for Thornton trips, but also carriesregional traffic to Denver International Airport(DIA). It is the only continuous east-west cor-ridor through the north-central part of themetro area.

Congestion on 120th Avenue is most severeat and near the I-25 interchange. This conges-tion results from the lack of another I-25interchange for six miles north of 120thAvenue, which places large demands on 120thAvenue, both from Thornton and Northglennto the east and from Westminster andBroomfield west of I-25.

Roadways with volumes within 20% oftheir approximate capacity, indicated onExhibit 8.4 as “Near Capacity,” include seg-ments of I-25, Washington Street, ColoradoBoulevard, 104th Avenue and 120th Avenue.

Critical Links The Plan identifies three critical links to

improve Thornton’s internal street system.Thornton Parkway, with missing segmentsboth east of Washington Street and West ofColorado Boulevard;

York Street, with a missing segment south of104th Avenue; andHolly Street, which currently terminates atRiverdale Road, approximately four blocksnorth of 104th Avenue.

Projected DemandsProjected traffic counts in the year 2020 are

illustrated on Exhibit 8.5. The projections,which are based on anticipated growth in thecommunity and region, were prepared usingthe transportation forecasting model devel-oped by DRCOG. The exhibit shows:1. The extension of E-470 to 120th Avenue,

scheduled for completion in 1999, willplace additional demands on 104th Avenuein Thornton. Forecasting with E-470 in

place south of 120th Avenue shows only arelatively moderate initial increase in trafficlevels on 104th Avenue in Thornton; how-ever, in the absence of a 120th Avenuecrossing of the South Platte River, trafficdemands and congestion on 104th Avenuecontinue to grow as development occurs inCommerce City and around DenverInternational Airport.

2. Based on existing development levels, theplanned 120th Avenue river crossing carriestraffic levels in the range of 15,000 vehiclesper day (vpd), creating a 5,000 vpd increasein 120th Avenue traffic at its interchangewith I-25. The river crossing carriesapproximately 20,000 vpd in 2020 assum-ing that the final phase of E-470 to I-25 isin place. Without the Phase IV E-470 com-pletion, 120th Avenue river crossing trafficdoubles and there is a sharp rise in demandson 120th Avenue through Thornton.

3. Traffic volumes on I-25 increase by approx-imately 40,000 to 60,000 vpd on varioussegments by 2020.

4. The Colorado Boulevard connection to andacross I-76 supports 30,000 vpd to 40,000vpd in 2020, providing increased accessibil-ity for residents in eastern parts ofThornton. The connection relieves severalroads in the southern part of Thornton,including 88th Avenue, 104th Avenue,Washington Street, and I-25.

5. With the exception of Colorado Boulevard,104th Avenue, and 120th Avenue, mostroads in the southern part of Thornton arestable or exhibit relatively moderate growthin traffic volume.

6. In the future, traffic on most arterial road-ways in northern Thornton exhibits sharpergrowth in anticipation of more develop-ment.

Major StreetImprovements

The Plan establishes a future roadway sys-tem to accommodate transportation demand inthe Year 2020. Exhibit 8.6 shows the func-tional classification and numbers of throughlanes for this system. Some of the most sig-nificant new improvements include the fol-lowing list of improvements:1. Completion of Phase IV of E-470, with

interchanges at I-25, relocated Washington

The Plan estab-lishes a future

roadway systemto accommodate

transportationdemand in the

Year 2020.


Chapter 8 8.7


Street, Colorado Boulevard, and QuebecStreet.

2. New I-25 interchanges at 136th Avenueand 144th Avenue, and supportingimprovements to both 136th and 144thAvenues through the City.

3. A South Platte River crossing of 120thAvenue east of Thornton, and supportingimprovements to 120th Avenue inThornton.

4. Widening of 104th Avenue through andeast of the City.

5. Extension of the I-25 Bus/HOV lanes tothe 144th Avenue interchange.

6. An extension of Colorado Boulevard fromThornton Parkway to a new interchangewith I-76, continuing south into VasquezBoulevard in Commerce City.

7. Roadway extensions connecting ThorntonParkway east of Washington Street andwest of Colorado Boulevard, York Streetsouth of 104th Avenue, and Holly Streetnorth of 104th Avenue.

8. Improvements to other mile-grid arterialstreets in the developing northern parts ofthe City.

Roadway Phasing Plan

Roadway improvement projects necessaryto implement the Roadway Plan are in fourphases, based on the projected timing ofdevelopment and travel demands. The pre-cise timing of project implementation needsto be adjusted over time, as Thornton and itssurrounding communities grow. As develop-ment occurs, the City preserves rights-of-wayfor the ultimate completion of the RoadwayPhasing Plan.

Phase 1 - Short RangeTransportation ImprovementsExhibit 8.7 illustrates the Improvements war-ranted by existing conditions. 1. I-25/120th Avenue Interchange: Widen

the northbound off-ramp by 1998.2. Thornton Parkway Connection: Extend

the Thornton Parkway east fromWashington Street to connect with itsexisting segment at Downing Street. Thisproject improves neighborhood accessibil-

ity and relieves local streets that currentlysubstitute for this missing connection.

3. Colorado Boulevard, from Welby Roadto 104th Avenue: Widen this two-lanesegment to create a consistent four-lanecross-section on Colorado Boulevard from88th Avenue to 136th Avenue by 1998.

4. 120th Avenue, Colorado Boulevard toCherry Street: Widen this short two-lanesegment to four lanes to create a continu-ous four-to-six lane arterial throughThornton between I-25 and Holly Streetby 1999, with federal funding.

5. 136th Avenue and 144th AvenueInterchanges with I-25: Conduct a studyto determine the location and timeline foradditional I-25 interchanges between128th Avenue and 144th Avenue.Agencies involved in the study includeCDOT, Thornton, Westminster, andBroomfield. (Thornton’s Future Land UseMap shows interchanges at 136th Avenueand 144th Avenue.)

6. I-25/120th Avenue InterchangeImprovements: Construct a two-lane exiton north bound I-25 at the 120th Avenueinterchange.

Phase 2 - Mid-Range Transportation Improvements

Exhibit 8.8 illustrates improvements trig-gered by short-term development in Thorntonand by other anticipated major roadway pro-jects, particularly the extension of E-470 to120th Avenue and the 120th Avenue crossingof the South Platte River. Thornton’s policydefers this crossing until an additional inter-change is constructed at I-25 and 136th or144th Avenue to provide relief for 120thAvenue traffic.7. Colorado Boulevard Connection:

Provide a four-lane extension of ColoradoBoulevard, extending southeast fromapproximately 96th Avenue to an inter-change with I-76. A feasibility study willevaluate needs and optimal configurationof this project. If the result of the feasibil-ity study is negative, then the project towiden 88th Avenue to four lanes east ofDahlia Street and to reconstruct the 88thAvenue/I-76 interchange becomes a medi-um-range improvement.

8. Thornton Parkway Extension: ExtendsThornton Parkway west from ColoradoBoulevard. This requires prior completion

Chapter 8 8.9


Chapter 8 8.11


of a conceptual plan for the ColoradoBoulevard connection.

9. York Street Connection: Connection ofYork Street as a two-lane collector from100th Avenue to 104th Avenue, whichimproves accessibility for existing andfuture residential developments.

10.104th Avenue Widening: Widen theexisting four-lane section to six lanes fromFranklin Street to Colorado Boulevard andof the existing two-lane section east ofColorado Boulevard to four lanes.Improvements to both of these segmentsare a result of existing traffic levels, andwill become higher-priority needs with theopening of an interchange at E-470 and104th Avenue.

11. Holly Street Connection: Construct anew two-lane roadway extending southfrom Holly Street near Riverdale Road toconnect with McKay Road at 104thAvenue. This connection carries approxi-mately 6,000 vpd in 2020 and moreimportantly reduces traffic levels and turn-ing activity on 104th Avenue betweenMcKay Road and Riverdale Road.

12.I-25 Bus/HOV Lane Extension: Extendthe I-25 High Occupancy Vehicle (HOV)lanes north from their present terminus at70th Avenue to 120th Avenue. This projectis being planned by RTD and CDOT.

13.I-25/120th Avenue InterchangeImprovements: Widen the 120th Avenuebridge to three lanes at the I-25Interchange only after a new I-25Interchange is completed north of 120thAvenue.

14.120th Avenue Widening: Widen theexisting four-lane segment fromWashington Street to Colorado Boulevardto six lanes and of the two-lane segmenteast of Holly Street to four lanes. Theseimprovements, particularly east of HollyStreet, relate to the 120th Avenue crossingof the South Platte River. The 120thAvenue/Washington Street intersectionwill require additional spot improvements.

15.136th Avenue and 144th AvenueInterchanges with I-25: Construct inter-changes on I-25 at 136th and 144thAvenues, based on the results of the I-25Interchange study identified as a short-range project above.

16.144th Avenue Improvements: Widen144th Avenue between I-25 and

Washington Street and pave the currentlyunpaved segment from Washington Streetto Colorado Boulevard. BetweenWashington Street and ColoradoBoulevard, 2020 forecasting only showsthe need for two lanes; however, this seg-ment is planned for an eventual four-lanewidth.

17.Washington Street Widening: WidenWashington Street from two to four lanesfrom 136th Avenue to 144th Avenue asthis corridor develops.

18.York Street Paving: Pave the two-lanesegment of York Street from approximate-ly 133rd Avenue to 144th Avenue, asdevelopment occurs.

19.Holly Street Paving: Pave the two-lanesegment of Holly Street from 120thAvenue to 144th Avenue, as developmentoccurs.

20.Quebec Street Paving: Pave the two-lanesegment of Quebec Street from 120thAvenue to 128th Avenue, as developmentoccurs.

Phase 3 - Long-RangeTransportation Improvements

Exhibit 8.9 illustrates changes triggered byanticipated development in the latter part ofthe planning period to 2020 and by the com-pletion of the final phase of E-470 to north I-25. 21.E-470 Completion to North I-25:

Construct the final phase of E-470 withaccess points at I-25, relocatedWashington Street, and relocated ColoradoBoulevard. Pending the outcome of adesign study for the final E-470 construc-tion, proposed alignments of intersectingstreets and interchange locations areshown in Exhibit 8.9. The use of the existing segment of StateHighway (SH) 7 east of I-25 and the exist-ing SH 7/I-25 interchange is a potentialalternative to the ultimate E-470 align-ment connecting with a new I-25 inter-change just south of 160th Avenue. Theuse of the SH 7 alignment as a cost-savingalignment is favored if it significantlyaccelerates the completion of E-470.

22.Washington Street & York StreetConnection: Pave 2-lane connectionbetween Washington Street and YorkStreet along 152nd Avenue to serve YorkStreet interchange on E-470.

Chapter 8 8.13


23.Colorado Boulevard Realignment:Realign Colorado Boulevard to improvesafety, buffer existing residential estatedevelopment in Wadley Farms andincrease the development potential sur-rounding the Colorado Boulevard/E-470interchange. This realignment will becontingent upon such factors as the timingof E-470 completion, funding availability,and future market conditions.

24.128th Avenue Widening: Widen 128thAvenue to four lanes between I-25 andClaude Court to accommodates develop-ment along the 128th Avenue corridor andto provide increased road capacity foreast-west traffic.

25.136th Avenue Extension: Construct136th Avenue as a two-lane street fromHolly Street to Yosemite Street, and con-nect Yosemite Street from RiverdaleDrive to 136th Avenue, as developmentoccurs.

26.144th Avenue Extension: Construct144th Avenue as a two-lane street fromHolly Street to Quebec Street, as develop-ment occurs.

27.Quebec Street Paving: Pave the two-lane segment of Quebec Street from 128thAvenue to 168th Avenue. Paving ofQuebec Street south of E-470 is a resultof development and construction of the E-470/Quebec interchange. While no sig-nificant development is anticipated northof E-470 along Quebec Street, paving thissegment will address dust on the busyunpaved road.

28.York Street Paving: Pave the two-lanesegment of York Street between 144thAvenue and 152nd Avenue and betweenSH 7 and 168th Avenue, as developmentoccurs.

Phase 4 - Improvements to complete the transportation system

The final improvement phase, illustrated inExhibit 8.10, consists of project needs thatare anticipated due to post-2020 develop-ment. Prior roadway projects allow for phas-ing toward these ultimate improvements:29.128th Avenue Widening: Extend the

four-lane section of 128th Avenue fromClaude Court to Colorado Boulevard.

30.136th Avenue Widening: Widen to fourlanes from Washington Street to ColoradoBoulevard.

31.144th Avenue Widening: Widen to fourlanes from Washington Street to ColoradoBoulevard.

32.Colorado Boulevard Widening: Widento four lanes from 136th Avenue to SH 7,along its planned northern alignment.

33.Bus/HOV Lane Extension: Extend theBus/HOV facility on I-25 to the 144thAvenue interchange. (This project is dis-cussed in the section on Mass Transit.)

Project Costs Exhibit 8.11 lists order-of-magnitude cost

estimates for the roadway projects whosecosts may be partially or fully borne by theCity of Thornton. Cost estimates were devel-oped using construction cost survey informa-tion developed by DRCOG for use in itsregional planning process. DRCOG costsper lane-mile for various roadway projecttypes were multiplied by roadway lengths toarrive at construction cost approximations.

The I-25 Bus/HOV lane project will befinanced entirely with federal, state and RTDfunds. The construction of E-470 will befinanced by the E-470 Authority. Since theCity of Thornton is not expected to directlyparticipate in funding for these projects, costsare not listed.

In addition to total project cost estimates,the exhibit lists costs that the City ofThornton may be expected to bear. Estimatesof Thornton’s cost shares are based on thefollowing assumptions:

For new or improved roadways through thedeveloping areas of Thornton, it isassumed that 75% of roadway costs wouldbe incurred by private developers, with25% of the costs falling to the City. Forsignificant roadway segments throughareas that are either already developed orare not planned to be developed within theplanning horizon, it is assumed that privatefunding would not be available and theCity would incur improvement costs forthose segments.For improvements on facilities classified asprincipal arterials or having higher classifi-cations, it is assumed that 60% of the costswould be paid for with federal or statefunds and 40% by Thornton or other localgovernments. This assumption is basedupon the traditional 80% federal/20% localfunding formula, tempered by the realiza-tion that full 80% federal funding is notlikely to be obtainable for all regionallysignificant projects.

Chapter 8 8.15


Exhibit 8.11: Transportation Improvements and Approximate Costs - CompleteTransportation Plan

Project From/To ImprovementType

Cost($millions)

1996dollars

Potential FundingParticipants

Short Range1 120th Ave. I-25 Interchange Widen ramp 1.1 State, Fed., Thornton

2 Thornton Pkwy. Washington toDowning New 2 lane 1.6 Thornton, Private

3 Colorado Blvd. Welby to 104th Widen 2 to 4 lanes 3.3 Fed., Thornton4 120th Ave. Colorado to Cherry Widen 2 to 4 lanes 1.4 Fed., Thornton

5 136th/144th Aves. I-25 Interchanges Study to determinelocations 0.35 Fed., Thornton

Westminster, Broomfield

6 120th Ave. I-25 Interchange Construct 2 laneexit NA

Phase Subtotal $7.75

Medium Range

7 Colorado Conn. 96th/Colorado to I-76 New 4 lane 14.2 State, Fed., Thornton,

Adams8 Thornton Pkwy. Steele to Colorado New 2 lane 1.6 Thornton, Private9 York St. 100th to 104th New 2 lane 2.0 Thornton, Private

10 104th Ave. Franklin to Quebec Widen 2 to 4,4 to 6 10.4 State, Fed., Thornton,

Northglenn

11 Holly St. 110th to104th/McKay New 2 lane 3.2 State, Fed., RTD

12 I-25 South City Limit to120th

Extend bus/HOVlanes NA State, Fed., Northglenn,

Thornton, Westminster

13 120th & 104th I-25 Interchanges ImprovementsTBD 10.0 State, Fed., Thornton,

Westminster

14 144th & 136th I-25 Interchanges New interchanges 17.2 State, Fed., Thornton,Northglenn

15 120th Ave. Wash. to Colorado,Holly to Quebec

Widen 2 to 4,4 to 6 8.9 Thornton, Private

16 144th Ave. I-25 to Colorado Pave E./4 lane W. 9.1 Thornton, Private17 Washington 136th to 144th Widen 2 to 4 lanes 3.0 Thornton, Private18 York St. 133rd to 144th Pave 2 lane 1.0 Thornton, Private19 Holly St. 120th to 144th Pave 2 lane 3.2 Thornton, Private20 Quebec St. 120th to 128th Pave 2 lane 1.1 Thornton, PrivatePhase Subtotal $75.0

Exhibit 8.11 is continued on next page

Local government shares for projects strad-dling borders with neighboring jurisdic-tions are allocated among jurisdictionsaccording to approximate proportions ofproject frontage.Some major roadway projects, such as newI-25 interchanges, may be partially fundedby creation of Special ImprovementDistricts. This funding mechanism is notconsidered in Exhibit 8.11; however, such

funding could be established to substitutefor funds listed under other public or pri-vate sources.The final column of Exhibit 8.11 shows

the resulting estimated City of Thornton costshares for each project. The total Thorntoncost is estimated at $57 million, including$49 million for projects in the first threephases. This translates to roughly $2 millionannual improvement costs for the City.

Exhibit 8.11: RoadwayImprovements andApproximate Costs

Chapter 8 8.17

Mass TransitExisting Service

Thornton currently is served by theRegional Transportation District (RTD) withnine local bus routes and six express orregional bus routes, in addition to specialevents service. RTD operates three park-n-Ride facilities that directly serve Thornton,including the Thornton park-n-Ride on eitherside of I-25 south of 88th Avenue, the park-ing lot at 104th and Washington (parkingagreement with property owner) and theWagon Road park-n-Ride southwest of 120thAvenue/I-25, just west of Thornton.Thornton residents can also use theBroadway park-n-Ride at 70th Avenue/

Broadway and the I-25 bus/HOV lanes thatcurrently extend from downtown Denver to70th Avenue.

A number of transit improvements are rec-ommended, including short-range recommen-dations to improve transit service for existingThornton residents and workers and longer-range recommendations to further expandtransit options and to extend service to devel-oping parts of the City.

Short-Range Mass Transit Improvements

RTD and CDOT have plans to extend the I-25 Bus/HOV lanes north through the I-76/US36/I-25 complex to 120th Avenue, as inter-change reconstruction and funding allow.

Exhibit 8.11 (con’t): Roadway

Improvements andApproximate Costs

Exhibit 8.11: Transportation Improvements and Approximate Costs - CompleteTransportation Plan

Project From/To ImprovementType

Cost($millions)

1996 dollars

Potential FundingParticipants

This portion of Exhibit 8.11 is continued from the previous page.Long Range

21 E-470 East City limit to I-25 ConstructFreeway NA E-470 Authority

22 Wash./YorkConnection

152nd St. from Yorkto Washington New 2 lane 12.9 Thornton, Private

23 Colo. Realign 144th to 168th New 2 lane 12.9 Thornton, Fed., E-470Authority, Private

24 128th Ave. I-25 to York Widen 2 to 4 lanes 4.5 Thornton, Private25 136th Ave. Holly to Yosemite New 2 lane 10.1 Thornton, Private26 144th Ave. Holly to Quebec New 2 lane 4.0 Thornton, Private27 Quebec St. 128th to 168th Pave 2 lane 5.3 Thornton, Private28 York St. 144th to 152nd Pave 2 lane 1.1 Thornton, PrivatePhase Subtotal $50.8Short, Medium and Long Range Subtotal (Through 2020) $133.55Medium Range29 128th Ave. York to Colorado Widen 2 to 4 lanes 3.0 Thornton, Private

30 136th Ave. Washington toColorado Widen 2 to 4 lanes 6.0 Thornton, Fed., Private

31 144th Ave. Washington toColorado Widen 2 to 4 lanes 6.0 Thornton, Fed., Private

32 Colorado Blvd. 136th to SH7 Widen 2 to 4 lanes 8.9 Thornton, Fed., Private

33 I-25 120th to 144th Extend Bus/HOVlanes NA State, Fed., RTD

Phase Subtotal $23.8Total $157.35

The Regional Transit Districtprovides bus service on nine

regular routes and six expressroutes in Thornton.

This facility will reduce travel times forThornton bus riders and carpoolers as it isextended to and through the City.

Thornton representatives have also workedwith RTD to develop conceptual bus routemodifications that will improve service in theCity. The following changes have beenincorporated in RTD’s draft 20 Year Plan,including:

Expand the coverage of theexisting Route 124 toward theeast, providing direct service tothe Mission Trace ShoppingCenter, the Thornton RecreationCenter, and several residentialneighborhoods. This willimprove both the inter-connec-tions among Thornton destina-tions and connection betweenThornton development andregional routes serving theWagon Road park-n-Ride. Thismay be initially facilitated by acall-n-Ride service. A call-n-Ride service is a convenientcurb-to-curb service, covering aspecific geographic areadesigned to supplement theexisting RTD service.

Establish a new Thorntoncirculator route (Route 89) con-necting the Thornton CivicCenter, Thornton Town Center,

and other destinations in Original Thorntonwith the Thornton park-n-Ride. This may beinitially facilitated by a call-n-Ride service.

One additional service improvement thatwould serve existing Thornton developmentis recommended for further exploration:

A peak period connection, perhaps as anextension of the proposed Route 89 describedabove, connecting the Thornton park-n-Ridewith the Broadway park-n-Ride. This wouldallow riders from the Original Thornton areato conveniently connect with the express andregional service that stops at the Broadwaypark-n-Ride, including routes to Boulder, theUniversity Hospital district in Denver, andthe Denver Technological Center.

Long-Range Mass Transit Improvements

The bus system should be expanded intonorthern and eastern Thornton as develop-ment occurs. Particular emphasis should be

placed on the mixed use and commercialareas in the north I-25 and E-470 corridors.

The extension of the I-25 Bus/HOV lanesbeyond their currently planned terminus at120th Avenue to 136th Avenue and to StateHighway 7 should be explored as those inter-changes are designed and the areas aroundthem are developed. A new park-n-Ride hasbeen planned at the 136th Avenue inter-change.

In addition to bus service, rail transit willbe an important component of the City’s masstransit system. Thornton plays a significantrole in two transit improvement studies in thenorthern part of the Denver Metro area andthe Northern Front Range area.

First, the North Metro TransportationMajor Improvement Study (MIS) chose theexisting Union Pacific Railroad that runsthrough Commerce City, Thornton andNorthglenn as their preferred alternative for atransit line. This alternative shows four sta-tions in the Thornton/Northglennn area.These are located at 88th Avenue and WelbyRoad, 100th Avenue and ColoradoBoulevard., 112th Avenue and York Street,and in Eastlake at 124th Avenue and ClaudeCourt. In addition, the study has two addi-tional future stations at 144th and York Street,and at 160th Avenue and ColoradoBoulevard. These are identified on the FutureLand Use Map, Exhibit 10.2 as transit stops.

Second, the North Front RangeTransportation Alternatives Study (NFRTAS)Major Improvement Study (MIS) focuses onthe transportation needs from Fort Collinsand Greeley south to Denver. One of thelocally preferred alternatives for this study isto have a commuter rail line that starts in FortCollins, moves southeast on existing rail linesto I-25 and links up with the existing UnionPacific Railroad Boulder-Denton Line. Thiscommuter line will travel south on this trackthrough Thornton, Northglenn and CommerceCity to the Denver Union Terminal. This pas-senger rail line shows one stop in theThornton area at 124th Avenue and ClaudeCourt, adjacent to the historic Eastlake area.This transit stop was also included in theNorth Metro Transportation ImprovementStudy and is shown on the Future Land UseMap, Exhibit 10.2 as a transit stop.

Thornton should seek to preserve the UnionPacific Railroad corridor for these or othersuch projects.


Chapter 8 8.19

As planned roadway connections in andaround Thornton are implemented, theyshould be incorporated into RTD’s bus rout-ing to increase transit efficiency and expandcoverage. Such opportunities include the useof the I-76-Colorado Boulevard connectionand the 120th Avenue crossing of the SouthPlatte River.

In addition to transit system improvements,development of ancillary services or “TransitOriented Development” at and around theexisting Thornton park-n-Ride and the poten-tial north I-25 park-n-Ride is recommended.Thornton should coordinate with RTD toexplore ways to spur commercial develop-ment that would make use of the park-n-Rides, and in turn the use of transit, moreconvenient. Such uses could include day carefacilities, convenience retail, small restau-rants, dry cleaning, and package/mailing ser-vices.

Regional ConnectionsThe City of Thornton transportation system

connects to a larger regional system of road-ways and mass transit routes. Thornton’s sys-tem must complement and fit within the larg-er system in order to be efficient and effectivefor the residents of the City and provide ade-quately for the growth of the community.

Many of the projects listed as Short-Range,Mid-Range, Long-Range and asImprovements to Complete the TransportationSystem are regional in nature and will pro-vide important connections to locations in themetropolitan area. The City of Thornton,however, has the following opportunities forinfluence on the regional transportation sys-tem.

The City participated in the development ofthe Adams County Transportation Plan, andThornton’s plan was integrated into their planfor all major roads. The Adams County planis a part of the DRCOG TransportationImprovement Program which addresses theentire metropolitan transportation needs.

The North Metro Transportation MajorImprovement Study and the North FrontRange Transportation Alternatives Study pro-vide important regional connections and havebeen discussed above.

Trails, Bikeways andPedestrian WaysSidewalks

The City currently requires the constructionof sidewalks along both sides of all publicstreets. Sidewalks along major and minorarterial and major collector streets arerequired to be detached from streets to pro-vide a buffer between pedestrians and movingtraffic. Continuous sidewalks are currently inplace on most Thornton streets. On some ofthe older street segments that pass throughundeveloped areas or older developed areas,sidewalk sections are absent. Thorntonshould continue its policy of adding side-walks as development, redevelopment, andstreet improvement projects occur in theseareas. Proper design, location and landscap-ing of sidewalks will encourage public use ofthese facilities as a means of transportationand recreation.

TrailsThe City is in the process of developing an

off-street trail system to provide a safe andconvenient alternative to the automobile forresidents to travel through the community.Trails serve residents of all ages, but are vitalfor the mobility of children and others whodo not have access to automobiles. While

trails should be designed as a communityamenity, transportation is a primary functionof a comprehensive trail system. Exhibit8.12 illustrates the approximate locations ofexisting and proposed trails throughoutThornton’s Planned Growth Area. Theseexisting and proposed trails either will con-

Trails serve residents of all

ages, but arevital for

children andothers who do

not have automobiles.

Bicycling enthusiasts enjoy manyscenic routes on both on-streetand off-street trails throughout

the community.


nect to existing trails in adjacent communitiesor are planned with connections in mind.This exhibit should be used during develop-ment review to reserve sufficient right-of-wayand to develop a continuous system of trailsfor bicycle and pedestrian traffic. The Cityshould use the annual capital improvementsplanning process to prioritize trail segmentsfor acquisition and/or improvement.

Goals and PoliciesThornton seeks to provide for a transporta-

tion system that allows for safe and efficientmovement through the community in a cost-effective manner. This means that the Citymust provide for a choice of modes of travelwith limited financial resources.Transportation investments will need to becoordinated with demands and with the abili-ty to fund such improvements. State and fed-eral funding will continue to be an importantresource, but increasingly, the City will needto look to the other sources of funding ifexisting levels of service are to be main-tained. The following goals and policiesdescribe the broad public purposes that thisComprehensive Plan seeks to achieve andestablishes steps to guide citizens towardsthose purposes.

The City of Thornton’s TransportationGoals are to:8-A Provide for safe and efficient movement

of people and goods within the City, aswell as to and from other communities.

8-B Maintain and expand the road system toprovide adequate capacity for motorizedtraffic in a cost effective manner.

8-C Provide for alternatives to single occu-pancy vehicles so all residents enjoy thebenefits of mobility through mass transit,trails and sidewalks.

8-D Enhance linkages between Thornton andother regional activity centers, such asdowntown Denver and DenverInternational Airport.

8-E Ensure that transportation improvementsenhance the overall quality of life withinthe community.

8-F Ensure that Thornton’s transportationsystem complements and fits within thelarger regional transportation system inorder to be efficient and effective for

City residents and that it provides ade-quately for the growth of the community.

The City of Thornton’s TransportationPolicies are to:8-1 Participate in State, regional and local

transportation system planning effortsand promote improvements that enhancethe vitality, safety and quality of life inThornton and promote regional roadwaysystem continuity and uniform design.

8-2 Work with appropriate agencies to sup-port the construction of major regionaltransportation improvements.

8-3 Work with appropriate agencies to expe-dite the construction of additional inter-changes on I-25 north of 120th Avenue.

8-4 Defer the eastward extension of 120thAvenue across the South Platte River toE-470 until additional interchanges areinstalled along I-25 north of 120thAvenue.

8-5 Educate citizens on transportation issuesand provide opportunities for citizeninvolvement in projects that impact theirneighborhoods.

8-6 Require all streets to be designed,aligned and constructed based on theirfunctional classification. When design-ing roadways:

Require all intersections and accesspoints to be aligned and spaced to pro-mote safe turning movements.Coordinate the dedication and develop-ment of collector streets to establishdirect and continuous east-west andnorth-south links between arterialroads. No collector street should forma loop to a single arterial street. Limit direct access from local streetsto arterial streets. Limit driveway access from landparcels to arterial and collector streetsto protect street function and safety.

8-7 Promote street system designs that miti-gate current and future traffic noise onmajor arterials.

8-8 Monitor traffic volumes, levels of ser-vice, and development trends on anongoing basis to anticipate neededimprovements to the local transportationsystem.

8-9 Support regional efforts to improve rail

Chapter 8 8.21

and bus service in the I-25 Corridor andthroughout the City. Support the provi-sion of services at park-n-Ride facilities.

8-10Require the local transportation systemto link housing, shopping, employment,parks, schools and civic facilities withroad and bicycle/pedestrian facilities.User safety, traffic flow and system con-tinuity should all be considered.

8-11 Coordinate with DRCOG and majoremployers in the City’s Planned GrowthArea to develop effective transportationdemand and systems management strate-gies to enhance the efficient movementof people, goods and services withinThornton’s Planned Growth Area.

8-12Develop a trail system and on/off-streetbicycle ways to provide an effectivealternative to the automobile.

8-13Use the Capital Improvements Planningprocess to logically sequence road andtrail improvement projects to serve antic-ipated growth.

Recommendations1. Evaluate adoption of a transportation

concurrency management program as aplanning tool to manage congestion onThornton’s major streets. Such a pro-gram should establish target levels of ser-vice along the City’s arterial streets.

2. Continue monitoring traffic volumes as ameans of identifying short-term capacityneeds.

3. Incorporate the Short-Range, Mid-Rangeand Long-Range improvements identifiedin this chapter into a Long-RangeTransportation CIP. This CIP should dis-tinguish costs for resolving existingcapacity deficiencies from the costs forproviding new capacity for future devel-opment.

4. Continue to coordinate and promote the

accelerated development of additionalinterchanges along I-25 at 136th and144th Avenues with CDOT, Westminsterand Broomfield. Use the North I-25 cor-ridor area plan process to identify poten-tial strategies to apportion costs based onthe benefits the interchanges will createfor adjacent properties.

5. Develop the trail system as a safe andconvenient transportation alternative forThornton’s residents to bicycle and walkbetween home, work, park, shopping andother facilities. Acquire trails through acombination of dedication and acquisi-tion strategies.

6. Support regional efforts to promote moreeffective transportation demand manage-ment. Adjust employee parking stan-dards to require preferential parking forcarpool participants.

7. Ensure that development adjacent to therail corridor is designed to be compatiblewith the long-term establishment of alight rail or commuter rail system in thecorridor.

8. Evaluate the establishment of a road util-ity in conjunction with the developmentof a major street impact fee.

9. Cooperate with agencies such as RTD onMajor Investment Studies, as well asother transportation planning efforts.


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