7.3 Version NERPMAB2

7.3 VERSION NERPM-AB2

This section documents the set of improvements that were made to the NERPM model for the release of NERPM-AB2. The improvements focused on:

Base year updated from 2010 to 2015
Re-built all land use inputs for 2015 and future
Switched from parcels to microzones to ease data preparation
Switched from PopGen to PopulationSim
Updated the highway network to 2015 (NFTPO)
Updated the transit network to 2016 (JTA)
Updated external traffic volumes and distributions based on Bluetooth OD data (FDOT)
Upgraded from the NFTPO specific version of DaySim to the multiple-agency (a.k.a. core) version, which is faster, more stable, and includes new features such as Transportation Network Companies (TNC) mode (i.e. Uber and Lyft)
Updated future year scenarios

Parcel to Microzone (MAZ)

In the previous version of the model, the unit of spatial analysis was parcels. There were approximately 700,000 parcels in the region, which made it difficult to maintain, edit and attribute, both the existing and alternative scenarios. This led to the creation and use of microzones as an alternative, which is halfway between parcels and TAZs and are easier to maintain. As you can see in the table, there are around 55 thousand microzones against 700 thousand parcels. This makes it much easier for the user to update land use information such as employment, enrollment etc. The total number of TAZs in this version is 1862. The plot shows the TAZ and the MAZ layer around downtown Jacksonville. This shows how TAZs and MAZs are related. You can see in the plot that MAZs in downtown tend to be smaller than the ones in the periphery. If you have any questions about the development of MAZs, please refer to the model documentation for more details.

County	Number of Parcels	% Freq	Number of MAZ	% Freq	Number of TAZ	% Freq
Baker	12,490	1.78	1,735	3.14	29	1.56
Clay	84,529	12.02	7,796	14.13	184	9.88
Duval	355,805	50.59	28,263	51.22	1,281	68.80
Nassau	47,443	6.75	4,455	8.07	108	5.80
Putnam	102,053	14.51	6,652	12.05	44	2.36
St. Johns	100,950	14.35	6,283	11.39	216	11.60
Total	703,270	100.00	55,184	100.00	1,862	100.00

Figure: MAZ and TAZ layer in Downtown Jacksonville

PopulationSim

PopulationSim is an open platform for population synthesis

Replaced PopGen in this version of NERPM-AB

Has better demographic and geographic methods compared to PopGen

Actively maintained by the travel modeling community

Run only when there are major changes in the landuse data

PopulationSim Wiki

In this figure, we see the performance of PopulationSim as it tries to match the controls. In this version of the model, controls such as household size, householder age, household income etc. were used at different levels of geography. The standard deviation (STDEV) of the percentage difference informs us of how much dispersion from the average exists. As you can see, the total number of households at the MAZ level matches perfectly with the controls. PopulationSim does that by design. And we see a very close match on all the other controls as well.

Model Calibration and Validation

The 2017 north florida travel survey and the 2016 onboard rider demographic survey were used to calibrate the model. Traffic counts and transit boarding counts were used to validate the model outputs.

Table: Population and Employment

County	2015 Population	2015 Employment	BEA 2015	2030 Population	2030 Employment	2045 Population	2045 Employment
Baker	23,138	9,649	9,695	32,340	15,876	37,723	20,123
Clay	189,600	68,871	69,317	263,882	120,166	321,984	156,073
Duval	854,757	624,952	623,596	1,078,136	786,052	1,231,564	888,333
Nassau	76,672	30,948	31,086	97,500	49,367	116,024	60,801
Putnam	71,687	22,605	22,780	78,328	34,695	84,790	38,102
St Johns	202,375	105,077	104,983	318,041	197,421	412,811	287,415
Grand Total	1,418,229	862,102	861,457	1,868,227	1,203,577	2,204,896	1,450,847