Missing Roads

There are 3 causes of roads being removed when transferring from MapRoad to Prime2. Each of these is listed below. Only the first case results in an, often temporary, loss of data, and many of these will be corrected automatically in future releases of Prime2.

Edges

Every edge in each LA is both automatically sorted, and then manually reviewed. Any junction-to-junction road (an edge), that is missing in Prime2 is added to an “Ignore” list (so it is ignored by the transfer scripts to move data from the MapRoad road schedules to the Prime2 roads dataset).

In some cases the roads have been added to MapRoad in the incorrectly, or they no longer exist. In other cases the roads have not yet been added to Prime2. As Prime2 is continually updated, many of these cases will automatically be fixed with future updates. If the roads is visible in the OSi (premium) layer in PMS then it will be added to PMS as part of regular updates, planned to start in late 2017.

The number of edges not transferred for each LA is listed at Manual Edits Summary

Segments

Once MapRoad edges have been mapped to Prime2 edges, the transfer process tries to create the segments (collection of edges), that correspond to a named road e.g. L-8336-0

As segments need to be continuous (and have no gaps or breaks), if any edges along the segment path are assigned to another segment then the segment cannot be recreated. In these cases the segment is displayed in brown on the map (as a “Legacy Road (to be fixed)”), and can be displayed in the Segments List using the “Is Legacy?” column as a filter.

Merged Segments

There are cases when two MapRoad edges need to be be merged together to a single Prime2 edge. Often these are cases where a roundabout has been digitised in MapRoad, but is a simple junction in Prime2. For example below, the MapRoad roads are displayed in red, and the Prime2 in black:

A section of the roundabout is then often merged with an incoming road. In the example above two of the edges being merged have different segment codes (R-772-646 and R-772-648), following the merge one of these segments would be lost completely.

Which segment code was kept was random for all LAs transferred up to the 09/06/2017 (it was simply based on the order entered into the database). Changes were made to the merging algorithm after this date so that whichever of the two segments had a longer length would be kept.

Note whilst the segment code may have been removed from the edge, any data associated with the segment (e.g. Works, Speed Limits, PSCI), will have been transferred onto the merged edge. The only data lost will be the link between the segment code and the edge. All the segment attributes will still be within the PMS system, but these segments will have no geometry, and a length of 0.

Filtering the Segments List with a Calculated Length of 0 will highlight many of these segments to fix/review, however this list will differ slightly from the report as some Segments also had a length of 0 in MapRoad (see table below).

Missing Merged Segments Summary

Below is a summary table listing the number of segments removed from each LA due to the merging process. Any LAs with identical zero lengths for MapRoad and Prime2 have not yet been transferred to Prime2.

Local Authority	MapRoad Zero Length	Prime2 Zero Length	Removed by Merge
carlow	177	177	0
cavan	1	1	0
clare	120	149	29
corkcity	3	6	3
corkcounty	144	212	68
donegal	143	182	39
dublincity	136	136	0
dunlaoghaire	54	115	61
fingal	182	182	0
galwaycity	334	334	0
galwaycounty	72	72	0
kerry	161	223	62
kildare	2134	2134	0
kilkenny	7	110	103
laois	20	22	2
leitrim	2	20	18
limerick	234	234	0
longford	23	23	0
louth	285	308	23
mayo	45	73	28
meath	14	14	0
monaghan	12	12	0
offaly	32	32	0
roscommon	72	72	0
sligo	73	87	14
southdublin	8	156	148
tipperary	164	164	0
waterford	42	733	691
westmeath	0	0	0
wexford	18	18	0
wicklow	15	190	175