Issue link: http://townofcary.uberflip.com/i/791958
To develop the street recommenda ons contained in this plan, future transporta on and land use condi ons were modeled to simulate traffic condi ons in 2040. The Triangle Regional Model (TRM), developed and maintained by the Triangle Regional Model Service Bureau was used to model current and future regional transporta on condi ons. The TRM is based on projected land use development for the en re Triangle region and a set of roadway and transit improvements planned out to 2040. The transporta on projects included in the TRM were developed as part of the 2040 Metropolitan Transporta on Plan (MTP) developed by the Capital Area Metropolitan Planning Organiza on. The MTP is fiscally-constrained, meaning the projects included in the plan are programmed within a budget of reasonably expected revenues. Also included in the MTP is the set of projects eligible to be included in the Metropolitan Transporta on Improvement Program (TIP). The TIP is a set of projects programmed to be implemented by 2020 that have specific funding sources and amounts allocated to them. To model the future traffic condi ons in the Town of Cary, modifica ons were made to the TRM land use and transporta on network within the Town of Cary limits, but data outside the Town of Cary was unaltered. Employment and popula on numbers were generated for the Future Growth Framework land use plan developed for this comprehensive plan and edited in the exis ng TRM. Edits were made to the TRM transporta on network to test the street recommenda ons envisioned in this plan. The Triangle Regional Model contains a number of assump ons about trip genera on, trip distribu on, mode of travel, and route choice. The model simulates traffic condi ons based on travel behavior assump ons and predicted street condi ons. A common measure of network func onality is the volume to capacity ra o (V/C), i.e., demand vs. supply. This represents the volume of traffic es mated to use a street segment compared to the capacity of that street segment. Capacity is a func on of many factors like number of lanes, speed limit, le -turn volumes, traffic signal density, and truck volumes, among other factors. The higher the volume/capacity ra o, the greater the conges on. A planning-level model analysis was performed at Level of Service (LOS) D, where LOS is measure of the traffic condi ons assigned a grade between A (least congested) and F (most congested). LOS D is typically the maximum acceptable conges on in urbanized areas. Generally, streets that are under capacity at LOS D (V/C < 1) have minimal conges on and streets that are at or above LOS D capacity (V/C => 1) have congested condi ons. In the map below, green and blue represent uncongested condi ons, yellow represents LOS D condi ons, and red represents over congested condi ons. Overall, the Future Growth Framework land use plan and the streets recommenda ons envisioned in this plan are compa ble. When examining the busiest hour of travel, the a ernoon peak hour, condi ons on most streets remain at or below acceptable levels of conges on. Where conges on in excess of acceptable levels occurs during the peak period, these condi ons typically do not extend beyond the peak hour. This indicates that the street plan and Future Growth Framework are compa ble. The planned street network is generally able to handle future expected demand. Complete model results analysis is included in the Technical Appendix. Future Conditions Modeling CHAPTER 7:MOVE 228